To everyone interested:

I managed to pull an Endurance from a MH2 pack, and I have the intention of adding it here. After pondering for a while if I should remove Flesh / Blood or Leyline of the Void , I decided to keep Leyline. My reasoning is as follows: Leyline is insane early game, but can make my remaining gravehate useless. This isn't a problem though, as I have no pure gravehate cards. Every single one of them has an alternate mode or is good enough without the hate already. When I drop Leyline late, it synergizes with my other gravehate in that it keeps graves empty once I cleared them. Flesh / Blood is a one-shot one-card gravehate that can alter as a Soul's Fire for 3 or 7 mana. Against decks where gravehate is important, that's a terrible rate, and only playing it for the creature removal isn't worth it. Endurance will usually be both a damage-based removal spell for an attacker and a one-shot full-grave removal for 3 or often even 0 mana. It can also be recursion for those grindy games where I really need lots of cards from my graveyard again. This is a strict upgrade and a welcome addition to the deck.

Soon-to-be Froghemoth may be solid addition considering the swiss-army grave-hate & chip-lifegain themes

Gleeock: Ooooh, great idea. Finally, a second card from the set I could use.

Liked for including Kazuul.

GrimlockVIII: Well, I guess good I included him :D

You asked me about recent adds. Karazikar, the Eye Tyrant slots in either your "Value" category or potentially "Survive" category as being Voltron'd is less of the threat with him & one big battlecruiser coming my way has been more of a problem for the spider than swing-wide. I added Fevered Suspicion because it is a fun bomb... but doesn't seem as on-point for you. Den of the Bugbear & Hive of the Eye Tyrant have been good utility lands for me.. One making more polymorph fodder. The other being more gravehate. Death Tyrant self-enables recursion & keeps the zombie train rolling.

Gleeock: Thanks, these are great suggestions. I've pulled hive from apack and actually considered adding it here. I'll do that now, but I'll have to think what to take out for it. A masic seems the easiest way, but then again, it's another potential tap land. Both beholders seem very interesting, but I stumbled into problems when I considered them: Death Tyrant, as cool as it is, doesn't really fit that well. Karazikar is a great card to support Thantis, and he also grants additional value. I even missed the anti-voltron tech. I decided against him before, but that changes things. I still have no idea what to replace with him, but I'll think about it.

The remaining suggestions are fine for Thantis in general. Thanks a lot for the feedback! :)

*A basic...

I'm getting more and more frustrated the more uninteligible my miss-spelling becomes -.-