Neat deck. Few things I thought of looking at it.
1) pretty sure Zada is female. Could be wrong, and totally irrelevant, but just thought I'd point that out.
2)
rush of vitality is nice, but it really forces you to use all thone different ways to create any mana for one black. I'd think about changing it for removal, like
harnessed lightning.
3) if you approve of 2, then you can also pull out
cryptolith rite, since you probably won't need creatures for mana. You could add
borrowed malevolence as another buff,
confront the unknown for draw and growing (I think that works with Zada, but I'm not sure.)
Just my .02$. Looks like that could be fun.