Preface
I have always loved slivers, even long before I ever learned how to play Magic: The Gathering. A single glance at the squiggly body of this strange creature I had never seen before was all it took and it was love at first sight! Long have I wished to create a deck fashioned around these fascinating creatures I could call my own. Finally, the time has come, and I've created not one, nor two, but in totality three different versions using the same core ideas! These range in power from casual fun, to high power, and lastly to semi-competitive. But they all have one thing in common: slivers!
This deck represents the final of those three lists, and is the result of my passionate attempt to create the most competitive EDH sliver tribal deck I possibly can at this time (April 23, 2024). Although there is little concessions made with regards to flavor, I do intend this to be a sliver tribal deck first and foremost, and not one that just so happens to feature a few slivers here and there between more impactful spells. The slivers must be front and center! As a matter of fact, I've made a deliberate effort to have all the win conditions fulfilled by slivers and slivers alone. That means combos such as those involving Wheel of Fortune with Underworld Breach, despite being easily supported (and in fact synergistic) within this list, are intentionally avoided.
So with those parameters established, I proudly present:
SLIVERIC
Just cuz it has my name, Eric, in it. Cheesy I know, but it's mine and I love it! That is, both my name and the deck! But just between you and me, you can call it whatever you like, I won't stop you.
The general idea of SLIVERIC is to either cheat Morophon, the Boundless into play from the graveyard to cast a lot of slivers for free as fast as possible or assemble all the pieces to one of many infinite combos. Both of these methods can be reliably facilitated by our commander, the Sliver Overlord, and its ability to tutor for any sliver we might need at the time we most need it.
With that in mind, let's take a closer look at the key cards in this list. Here goes!
Commander
This is none other than the positively brilliant, the supremely stupendous, the...uh...ridiculously...er...handsome (?)...Sliver Overlord! Why you ask? Well I'm glad you did, because our commander can fulfill any need you can possibly think of! Need slivers? Check! Need more slivers? Check! Need even more slivers? Of course you do! A one-card army, our commander does it all!
What's really great about Sliver Overlord is that it makes for an ideal infinite mana outlet (since its abilities don't require tapping)! Even in the case of colorless mana, just pay three to first find Morophon, the Boundless (who requires no colors to cast) and then subsequently search for and cast any and all slivers in the deck since Morophon reduces the colored mana costs of all our slivers! And opponents beware because if infinite colored mana is achieved at any time (of which there are many ways), Sliver Overlord makes this deck nigh unstoppable! You can simply use the mana to first cast it from the command zone before using its tutoring ability to take it from there! Having that ever-accessible mana outlet via our commander is, just like, so cool!
Ladies and gentleman, please give a round of applause for the one and only Sliver Overlord!
Creatures
Morophon, the Boundless
One of the centerpieces of SLIVERIC, Morophon allows us to cast many slivers, including our commander, for free!
Since it's expensive to hard-cast, we'd prefer to cheat this legendary changeling into play. Entomb, Buried alive, Survival of the Fittest, Wheel of Fortune and Homing Sliver (via slivercycling) can help Morophon find its way into the graveyard from which Reanimate, Life/Death, Dregscape Sliver or Yawgmoth's Will can resurrect it to the battlefield.
The least mana-intensive way to have Morophon hit the field requires two cards. Entomb followed by either Reanimate or Life/Death will do the trick. Quick, simple and effective.
One valid strategy is to use Survival of the Fittest to discard any creature from your hand to fetch Morophon, the Boundless, that is unless it's already in your hand. If so, then just skip to this next step because once it's in your hand, activate Survival of the fittest to discard our favorite changeling to search for Dregscape Sliver. Voila! We now have the means to unearth all our slivers in the graveyard, Morophon included! Homing Sliver's slivercycling works much in the same way. Both do it all in just one card!
Perhaps even easier is casting Buried Alive to put Morophon, Dregscape Sliver, and another suitable sliver into the graveyard. Unearth Dregscape Sliver and then Morophon, the Boundless becomes bound no more! One card to rule them all, Buried Alive works wonders in this list!
There's another great way to get the job done, and this one's explosive! But also risky. It involves the meticulous utilization of a spectacular activated ability possessed by a creature known only as the Hermit Druid by man and beast alike in order to brazenly and deliberately mill the entirety of your library since, well uh, we ain't got nun of dose durned basic lands in dis 'ere deck! Oh yeah, and you'll probably want Yawgmoth's Will too (unless you have lots of mana to unearth all your beautiful sliver beasties!). Cast it, then activate Hermit Druid's ability (in that order, lest you want to risk losing a crucial card in your graveyard to instant-speed exile). Follow up with Reanimate on Morophon, the Boundless. Since you can play all cards from the graveyard this turn as though they were in your hand, and Morophon reduces the cost of all slivers, well guess what? All your other slivers become boundless too! Comes complete with counterspell protection to boot (courtesy of your very generous graveyard). Or as is always when an opponent tries to stop you from popping off, just cast Quick Sliver in response and continue on your merry way to the promised land.
Sliver Queen
Maybe the most common and effective means by which we win is with combos revolving around Sliver Queen. Good news! The aforementioned strategies revolving around Survival of the Fittest, Homing Sliver and Buried Alive also work to assemble the various Sliver Queen combo lines! Yay!
Generally you'll want one or more of Dregscape Sliver, Basal Sliver, Lavabelly Sliver and of course her heinous the Sliver Queen either in your hand or on the battlefield, and the rest in your graveyard. Just try to avoid keeping the more costly to cast of these in your hand, unless Morophon's already in play.
Buried Alive and/or Survival of the Fittest are your friends here. First, let's take a look at the latter. It goes like this: Pay (G) to activate Survival of the Fittest, discarding any creature card from your hand in the process to search your library for Sliver Queen/Basal Sliver/Lavabelly Sliver (best done during opponent's end step). Pay (G) and discard the newly acquired sliver to find the second of Sliver Queen/Basal Sliver/Lavabelly Sliver. Repeat this process again to tutor for the third and final remaining sliver. Activate the ability for the last time to seek Dregscape Sliver so that you may cast it from your hand. Abra kadabra alakazam, and just like that the Sliver Queen line is assembled in your graveyard, ready to unearth! Of course, this process goes quicker if you already have any of these slivers in your hand or on the battlefield to begin with. Homing Sliver operates similarly.
Buried Alive simply requires you to have at least one of theses four slivers either in your hand or on the battlefield to function properly. Put the other three into your graveyard so you may unearth at an opportune time.
Yawgmoth's Will can also get the job done in a variety of manners. Reanimate, Life/Death, tutors, the choice is yours.
Emiel the Blessed
Although technically not a sliver (blasphemy!), the synergy Emiel has in this list is undeniable. One of the central strategies of SLIVERIC involves the abuse of activated abilities (namely our commander's). As such, cards like Training Grounds and Zirda, the Dawnwalker serve to facilitate said core strategy. Emiel the Blessed, already a strong card of its own accord in many competitive decks, further takes advantage of these cards' inclusion for the sake of its own powerful activated ability, which when paired with Dockside Extortionist, Intruder Alarm or Mana Echoes, can readily produce infinite mana. And we like infinite mana!
Besides being a crucial piece in several combos, Emiel does a lot of work in this deck. Would you like to save another creature you control from targeted removal? Care to untap one of your critters at instant-speed for a myriad of uses? Are you partial to ETB triggers? How about declaring blockers and then removing them from combat before damage is dealt? Emiel is here for all your needs. What's more is that blinking a creature otherwise doomed to eventual exile due to unearth in fact saves it from said exile! In this deck, methinks that just might come in handy! Oh, and negative auras attached to creatures are removed in the process. Not too shabby eh?
I suppose another idea is to pay for one +1/+1 counter to put on Esper Sentinel (or two if Amoeboid Changeling transforms it into a unicorn before the ability resolves!) for likelier card draw. On that note, remember that both changelings in the deck are granted two +1/+1 counters if you pay for Emiel the Blessed's triggered ability in response to either entering the battlefield.
Card Selection
Amoeboid Changeling
Oh boy, where to start? Firstly, it has all creature types and therefore benefits from all sliver perks. Yay! This also doubles as an on-brand tribal substitute for Gilded Drake when Sliver Overlord is on the battlefield since it allows us to gain control of creatures our opponents control using our commander's second activated ability. Certainly, this adds much more tribal flavor and makes better use of our commander to boot! What's really cool is this effect is easily repeatable as you can do it at least once per turn, more if you can untap via Intruder Alarm, blink it with Emiel the Blessed or return it to hand and recast with haste. Heck, you could even sacrifice it and gain mana or destroy a permanent in the process via Basal Sliver and Necrotic Sliver's respective abilities and then unearth it a la Dregscape Sliver, which automatically provides haste! Just keep in mind, if Crystalline Sliver is in play, this strategy will no longer work as transforming an opponent's creature into a sliver will give it shroud (although you can always use the above methods to temporarily remove Crystalline Sliver from play if need be). On the flip side, you can use Amoeboid Changeling to spread shroud or indeed any other sliver abilities to non-sliver creatures you control to protect or enhance them in some way. Giving haste to Bloom Tender, the option to tap for mana to other creatures, or providing Sliver Legion's buff to Esper Sentinel for near-guaranteed card draw can all be great moves, but best of all is the combo it enables with Dockside Extortionist and Hibernation Sliver. Simply transform the former into a sliver and then use the latter's ability to send the goblin-turned-sliver back to hand. Now you can recast it for that beautiful ETB effect again! If it generates at least four treasure tokens (or even less with Intruder Alarm, Mana Echoes, or Morophon, the Boundless on the field), you can repeat this process so long as you have enough life to do so, although this might require haste or ETB untap. Just return Amoeboid Changeling to hand via Hibernation Sliver so that it may enter the battlefield untapped once again. Of course, Intruder Alarm makes all this so much cheaper and easier. This quasi-sliver also synergizes extremely well with mana echoes, multiplying mana gain for every non-sliver you control by virtue of being all creature types. Also, as is the case with all blue cards, it can be pitched to Force of Will. Not super relevant but a fun fact is Amoeboid Changeling counts as a unicorn so would gain two +1/+1 counters from Emiel the Blessed!
Arcane Adaptation
This card serves to homogenize the deck's entire creature base into slivers, which is a major flavor boost! More importantly, it provides us a host of benefits. How would you like all your creatures to have haste (excellent for mana dorks like Bloom Tender)? Ditto for flying, shroud, indestructible, unearth, cascade, card draw and the ability to tap for mana or be sacrificed for the good of all sliverkind. Just imagine what kind of damage Sliver Legion could wreak with such a force, especially when paired with Death/Life! World-ending to be sure! What's more is it enables us to tutor for Dockside Extortionist, Emiel the Blessed and Zirda, the Dawnwalker via our commander or slivercycling. Bouncing Dockside Extortionist has never been easier, courtesy of Hibernation Sliver. And now Dregscape Sliver allows you to unearth it for a repeated ETB. Let's see, what else? Oh yeah, Morophon, the Boundless can now apply its cost-reducing effect to all our newly reformed slivers, so that's cool! It also makes Mana Echoes happy and can be fed to Force of Will so all in all a worthy include.
Archivist of Oghma
Beyond the usual instances where it will draw you a card, this synergizes well with Assassin's Trophy and Boseiju, Who Endures.
Boseiju, Who Endures
This land taps for green, which is the most represented color in this list, but also has utility as removal for problematic artifacts, enchantments and/or non-basic lands. What's more is that since Channel is an activated ability, not a spell, it can't be countered by usual means!
Chain of Vapors
This is a very versatile card in this deck. First of all, it makes for excellent instant-speed removal of any problematic nonland permanent an opponent controls. It can also bounce your own permanents to protect from removal (great with Morophon, the Boundless on the field) or return tapped mana-positive rocks like Chrome Mox, Mox Diamond, Sol Ring, Mana Crypt or Grim Monolith to your hand (hasted mana-dorks also work!). Need I mention Dockside Extortionist? Other ETB effects synergize too (looking at you Dormant Sliver)! Sac your tapped out lands to do this if you need extra mana to combo out that turn. Would you like to increase the storm count for Flusterstorm? Chain of Vapor's got your back! It even has the potential to be used as a political piece in multiplayer games. By targeting the second most threatening permanent at the table, you encourage that opponent to sacrifice a land so that they may copy it to remove the most dangerous threat. Should that occur, you'll have removed two nasty permanents and a land with just one spell! And all of this is possible for only one blue mana! Oh yeah, did I mention it can feed a Force of Will?
Dormant Sliver
This sliver can create substantial card advantage over the course of a game if left unchecked. Despite the many infinite combos in this deck, only this card can enable unlimited draw. It does have two inherent disadvantages, both of which are easily mitigated. The first is sharing defender with all slivers. Sacrificing via Basal or Necrotic Sliver, or bouncing back to hand courtesy of Hibernation Sliver (and a slew of other spells) completely circumvents the issue. Or you know, just shrug at defender as you combo out to victory. The second is that its casting cost is slightly high at four mana total. Morophon says hi, then takes half of it away. The good news is that its blue, and so is a worthy sacrifice to Force of Will. Most importantly, its a sliver and can do all those great slivery things like tap for mana and cascade.
Hibernation Sliver
This sleepy lil critter more than earns its keep in this deck. It can save all your slivers (itself included) from spot removal and boardwipes alike at no mana cost! With Morophon, the Boundless in play you'll be able to recast the majority for free (and at instant speed should Quick Silver be involved)! This interaction can also net you some extra mana or card draw in a pinch with ETB and hasted mana-dork slivers that have already tapped out this turn. Blue in its color makes it compatible with Force of Will so that's always a plus. Oh and make sure to read Amoeboid Changeling's description for a repeatable synergy involving it alongside Dockside Extortionist. Same goes for Arcane Adaptation.
Life / Death
I used to run a copy of Animate Dead in this list, but then discovered Death does nearly the same thing for the exact same mana cost, and without the inherent risks involving enchantment removal. Not only that, but it's far more versatile. Life allows for some great interaction with Intruder Alarm (since now your all lands will untap whenever a creature enters the battlefield), Arcane Adaptation (especially alongside Mana Echoes or Sliver Legion) and Emiel the Blessed (by blinking Gaea's Cradle).
Otawara, Soaring City
This land taps for blue, which is the second most represented color in this list, but also has utility as removal for problematic permanent creatures, artifacts, enchantments and planeswalkers. This can even target lands that share any of those types! What's more is that since Channel is an activated ability, not a spell, it can't be countered by usual means! Zirda, the Dawnwalker alone reduces the cost to just one blue mana by virtue of it being legendary on top of its static ability!
Pongify
This is removal that's also ramp in disguise with Intruder Alarm on the field. Or you can use it to untap all creatures before declaring blockers. You can even target one of your own creatures in a pinch (if you really need mana or to save it from exile). This is especially effective in conjunction with Sliver Hivelord because although the target won't be destroyed, you'll still get an Ape token. Colorless mana can also be gained using this method if both Arcane Adaptation and Mana Echoes are in play. If need be, exile it to pay Force of Will's alternate casting cost.
Quick Sliver
Granting flash to all your slivers is so empowering. You can flash in the appropriate response in sliver form as needed at instant speed. Targeted removal? Crystalline Sliver says hi! Boardwipe? In comes Sliver Hivelord! No blocks? Sliver Legion might make your opponents regret that. It also enables you to avoid disruption by responding to any opponent's spells at instant speed and continue combo chains uninterrupted.
Swan Song
This is a counterspell that's also ramp in disguise with Intruder Alarm on the field. Or if good fortune allows, you might be able to use it to untap all creatures before declaring blockers. You can even target one of your own spells in a pinch (if you really need mana). This is especially effective in conjunction with Cavern of Souls or Veil of Summers because although the target won't be countered, you'll still get a Bird token. Colorless mana can also be gained using this method if both Arcane Adaptation and Mana Echoes are in play.
Veil of Summer
Beyond the obvious utility of this card, I'd like to point out that casting this in response to a copied Chain of Vapor protects all your permanents (so your opponent sacrificed a land for nothing ha!) and guarantees you a card draw.
Yawgmoth's Will
This is a game-winner in conjunction with Hermit Druid. Besides the previously described method of casting every single sliver in your deck from your graveyard for virtually free, there's also a recipe for fast mana to be found in there! Mana Crypt, Sol Ring, Grim Monolith, Chrome Mox, Mox Diamond, plus playing any land can take you places! Discard engines like Survival of the Fittest and Homing Sliver, as well as Wheel of Fortune, can fill your graveyard with all kinds of goodies (like free counterspells)!
Zirda, the Dawnwalker
This legendary creature is a major boon to all the strategies in this deck! It not only reduces the cost of both our commander's activated abilities, but also those of the ever-important Sliver Queen, Dregscape Sliver (including all subsequent unearth costs!), Homing Sliver, Necrotic Sliver, Emiel the Blessed, Boseiju, Otawara and Grim Monolith (which can net infinite colorless mana!). Also, making one (or more if untapped via Intruder Alarm) creature(s) unable to block can be relevant.
List of Infinite Combos
Sliver Queen + Mana Echoes + (2) colorless mana = instant speed infinite ETB, infinite tokens, infinite colorless mana
[Add Lavabelly Sliver, Dormant Sliver, or Necrotic Sliver to the equation for infinite non-combat damage, card draw or permanent destruction respectively]
Sliver Queen + Basal Sliver + Lavabelly Sliver + (2) colorless mana/any sacrificial sliver = instant speed infinite ETB, infinite non-combat damage, infinite lifegain, infinite LTB
Sliver Queen + Basal Sliver + Dormant Sliver + (2) colorless mana/any sacrificial sliver = instant speed infinite ETB, infinite card draw, infinite LTB
Sliver Queen + Basal Sliver + Training Grounds/Zirda, the Dawnwalker + (1) colorless mana/any sacrificial sliver = instant speed infinite ETB, infinite tokens, infinite LTB, infinite black mana
Sliver Queen + Basal Sliver + Training Grounds/Zirda, the Dawnwalker + Cloudshredder Sliver + (1) colorless mana/any sacrificial sliver = instant speed infinite ETB, infinite tokens with haste, infinite LTB, infinite black mana
Sliver Queen + Basal Sliver + Cloudshredder Sliver + Gemhide Sliver/Manaweft Sliver + (2) colorless mana/any sacrificial sliver = instant speed infinite ETB, infinite tokens with haste, infinite colored mana, infinite LTB
Emiel the Blessed + Dockside Extortionist + (4) opponent artifacts/enchantments + (3) colorless mana = instant speed infinite ETB, infinite treasure tokens, infinite LTB
Emiel the Blessed + Dockside Extortionist + Zirda, the Dawnwalker/Training Grounds + (2) opponent artifacts/enchantments + (1) colorless mana = instant speed infinite ETB, infinite treasure tokens, infinite LTB
Emiel the Blessed + Mana Echoes + (4) slivers + (3) colorless mana = instant speed infinite ETB, infinite colorless mana, infinite LTB
[Less if slivers have haste and can tap for mana]
Emiel the Blessed + Mana Echoes + (2) slivers + Zirda, the Dawnwalker/Training Grounds + (1) colorless mana = instant speed infinite ETB, infinite colorless mana, infinite LTB
[Less if slivers have haste and can tap for mana}
Emiel the Blessed + Intruder Alarm + (4) mana-producing creatures + (3) colorless mana = instant speed infinite ETB, infinite colored mana, infinite LTB
Emiel the Blessed + Intruder Alarm + Zirda, the Dawnwalker/Training Grounds + (2) mana-producing creatures + (1) colorless mana = instant speed infinite ETB, infinite colored mana, infinite LTB
Zirda, the Dawnwalker + Grim Monolith (untapped) = instant speed infinite colorless mana
Zirda, the Dawnwalker + Grim Monolith (tapped) + (2) colorless mana = instant speed infinite colorless mana
List of Finite Combos and/or Synergies
Morophon, the Boundless + Sliver Overlord + (3) colorless mana = repeatable tutor and subsequent free casting of slivers
Morophon, the Boundless + Sliver Overlord + Zirda, the Dawnwalker/Training Grounds + (1) colorless mana = repeatable tutor and subsequent free casting of slivers
Sliver Overlord + Zirda, the Dawnwalker + Grim Monolith (untapped) = infinite colorless mana (use to tutor for Morophon, the Boundless via Sliver Overlord first, then cast every sliver in the deck)
Amoeboid Changeling + Hibernation Sliver + Dockside Extortionist + Cloudshredder Sliver + (5) opponent artifacts/enchantments + (2) mixed mana + (4) life = repeatable ETB, repeatable treasure token generation, repeatable LTB
[(1) less opponent artifact/enchantment required if Morophon, the Boundless is in play]
Amoeboid Changeling + Hibernation Sliver + Dockside Extortionist + Intruder Alarm + (3) opponent/enchantments + (2) mixed mana + (2) life = repeatable ETB, repeatable treasure token generation, repeatable LTB
[less requirements if mana-dorks are on the field]
Amoeboid Changeling + Hibernation Sliver + Cloudshredder Sliver + Dockside Extortionist + Mana Echoes + (3) opponent artifacts/enchantments + (2) mixed mana + (4) life = repeatable ETB, repeatable colorless mana generation, repeatable treasure token generation, repeatable LTB
[(1) less opponent artifact/enchantment required if Morophon, the Boundless is in play]
Hibernation Sliver + Dockside Extortionist + Arcane Adaptation + (3) opponents artifacts/enchantments + (2) mixed mana + (2) life = repeatable ETB, repeatable treasure token generation, repeatable LTB
[(1) less opponent artifact/enchantment required if Morophon, the Boundless is in play]
Smothering Tithe + Wheel of Fortune = (7) cards drawn + (7) potential treasure tokens per opponent
Intruder Alarm + Pongify/Swan Song/Forbidden Orchard (tap) = untap all creatures
Intruder Alarm + Life/Death + Creature ETB = untap all creatures and lands
Mana Echoes + Life/Death + Arcane Adaptation + Creature ETB = (X) colorless mana
Dislaimer
Due to the nature of adhering to a specific theme (in this case, Sliver Tribal), this deck is unlikely to win any truly top-tier cEDH games. That being said, the interaction package is designed to contend with cEDH meta and is therefore extremely focused and specific to the strategies found there. This may make it less optimally positioned to deal with non-cEDH threats. Substituting certain cards that are extremely powerful in competitive play, but less so in casual games, might actually improve the overall performance in the meta where this deck is most at home: high-power Commander. The idea here is that this is a sliver tribal deck list optimally designed to be as competitive as possible at a cEDH table.
Flex Slots
The quest for perfection is never complete and so it is that there are perhaps several substitutions that could be made should I ever truly wish for this deck to achieve its absolute maximum potential (at the expense of losing even more flavor and/or sacrificing sub-optimal strategies that may currently exist primarily for tribal synergy). Likewise, if you're hellbent on crafting the absolute most competitive sliver tribal list ever imaginable and wish to use this deck as a foundational starting point, I might suggest experimenting with these flex spots:
Amoeboid Changeling: Gilded Drake is probably the superior choice strictly when it comes to gaining control of target creature an opponent controls.
Bloom Tender: You may opt for other ramp such as lower-cost, lower-reward mana-dorks, enchantments like Wild Growth, mana rocks like Arcane Signet or spells like Three Visits.
Brainstorm: While this is probably the best cantrip in the format, a card advantage engine suited to the meta might generate more value overall.
Boseiju, Who Endures: If you feel like you need stronger mana fixing amongst your land base you could consider cutting this.
Carpet of Flowers: Replace in the unlikely event that blue is completely absent from the meta.
Deflecting Swat: Our commander CMC is fairly high and the deck might be better served with other countermagic or interaction.
Dormant Sliver: There are many amazing card advantage engines out there, and I'm not sure if Dormant Sliver is the absolute best in class for this deck.
Fierce Guardianship: Our commander CMC is fairly high and the deck might be better served with other countermagic or interaction.
Gemstone Caverns: Do I feel lucky? Well, do ya, punk?
Green Sun's Zenith: There exist many great tutors such as Finale of Devastation and Eldritch Evolutions so pick the best one for your meta.
Grim Monolith: Goes infinite with Zirda, the Dawnwalker so if one is cut, so should the other. Mana Vault is an excellent replacement.
Haste Sliver: Haste is excellent for enabling many combos in this deck much more readily, but is redundant with Cloudshredder Sliver so could be cut in favor of whatever is felt to be missing.
Harmonic Sliver: Sometimes this sliver does more harm than good so this one's debatable. Still an excellent addition to any sliver deck in my opinion. Flash it in with Quick Sliver for appropriately devastating results, or ground its double-edged ETB effect with an indestructible artifact like The One Ring.
Homing Sliver: Certainly fits the synergy of this deck, but sometimes the raw power of many cEDH staples cards are the optimal choice in the format. As far as tutors go, there's some stiff competition out there.
Mana Echoes: If you start cutting some of the slivers then this might not generate enough value for four mana. Also, producing only colorless mana can sometimes be restrictive.
Otawara, Soaring City: If you feel like you need stronger mana fixing amongst your land base you could consider cutting this.
Sliver Hivelord: If your meta is light on destroy effects and combat damage, then this staple sliver might not be strictly necessary.
Sliver Legion: If the vast majority of the time you could swing lethal with this a Sliver Queen line will win the game anyway, then this staple sliver might not be strictly necessary.
Smothering Tithe: This is here mainly as a way to punch above your weight class against top-tier cEDH decks should you manage to resolve either Timetwister or Wheel of Fortune with it on the battlefield. If those wheel effects are subbed out, likely this goes too.
Timetwister: A risky and situational card so perhaps other draw spells will serve the deck more consistently. This is here mainly as a way to punch above your weight class against top-tier cEDH decks should you manage to resolve it with Smothering Tithe on the battlefield, or to save you from falling flat on your face in the event that something goes wrong after activating Hermit Druid.
Veil of Summer: Replace in the unlikely event that blue and black are completely absent from the meta.
Yawgmoth's Will: While an excellent card, this could be swapped with Underground Breach to combo with Wheel of Fortune. As I said in the preface, I wish for all win conditions to be of the slivers, by the slivers, for the slivers. Should you feel differently, please feel free to adjust accordingly.
Wheel of Fortune: A risky and situational card so perhaps other draw spells will serve the deck more consistently. This is here mainly as a way to punch above your weight class against top-tier cEDH decks should you manage to resolve it with Smothering Tithe on the battlefield, or to discard Morophon, the Boundless/Sliver Queen into your graveyard.
Zirda, the Dawnwalker: Biomancer's Familiar might be more favorable due to its lower CMC, although many perks will be lost in the transition.
Thanks for stopping by!
Please let me know if you have any suggestions! Any feedback is greatly appreciated!
