Your deck also seems very fragile to aggro. Not knowing what your budget is, I might look into some high toughness creatures such as Sylvan Caratid (1G, 0/3 hexproof creature that can be tapped for one mana of any color),
Omenspeaker (1U, 1/3 scry 2 when it enters the battlefield). I also think that you don't need
cranial Archive in the main. It could be better off in the Sideboard. Sulita didn't really get any good boardsweepers, so maybe give
Extinguish All Hope (4BB Sorcery, Destroy all non-enchantment creatures) a try, although it won't kill Master of the Feasts. I don't really see the reason for Nissa other than her ability to make 4/4's.