These are cards you should consider. Undying Flames is a crazy combo with this commander since it copies the epic trigger, Precursor Golem is a solid value card for this deck, Seize the Day is very strong and even more so if you can find a way to give vigilance or untap your creatures for more combats, Twinflame and Heat Shimmer will double up your creatures and allow you to alpha strike your opponents.

Oh Also I feel I should point out that Soul's Fire does not work with this commander. The problem is that it will target another creature or player and if the spell has more than one target Zada can't copy it.

Thanks for the note about Soul's Fire and the suggestions. I'll replace it with a Mountain for now until I can get something ordered.