BFJaor

Hooded Hydra might be good to add. Get a big creature, and if it somehow dies, you get tons of little creatures.
Kalonian Twingrove could work too.

I think Maelstrom Pulse can be replaced. There are better kill spells in mono black that are cheaper and instants instead of sorcereries.

Nice. I would also consider Sekki, Seasons' Guide, Cyclonic Rift, Fable of Wolf and Owl, and maybe Biomantic Mastery, and Cytoplast Manipulator/Root-kin. Some of those may not help so much with evolve though....just something to consider.
Also, there's probably a better replacement for Goliath Sphinx.

You're focusing life gain so much. Don't go to the extent that the deck has solely life gain.

Why cloudstone curio? Some of these creatures imo are redundant because of trostani's ability. You may be going a little overboard with the life gain.

Add craterhoof behemoth. An almost definite win con. The splicers are also good (master splicer, blade splicer, etc.). collective blessing can work pretty well too, everything getting +3/+3.

Add more huge creatures (i.e. Ulamog, Kozilek, Blightsteel, Darksteel, colorless creatures that when animar gets big enough you can play for absolutely free). Some of the evolve things like the krasis and gyre sage are not really worth it, and you dont need so much mana since you have animar to reduce their cost. Ornithopter and Memnite are good for free counters also. The token generators are worthless too. They arent being cast, and animar does NOT get tokens from them.

You want to risk turning your slivers into walls? Dormant sliver isnt that great. lurking predators is a good addition. YOu can play slivers off the top of your deck when someone plays a spell. I would think about replacing dream thrush and dreamscape artist with slivers too.

Could you explain to me how your deck works please? I kinda want to try him out as a commander.
Plus, how quickly do you get her out? Isn't mana an issue, i mean she is 7 mana.

It's not?!

Why Illusory Angel? And are you making this based around evolving all your creatures?
Biovisionary is useless unless you want to make tokens of it, and you dont have much to tutor for it or the spells to make tokens.

Ah, but illusionist bracers DOES work on Mayael. I thought it wouldnt work either, so i looked it up, and a "mana ability" is considered and ability that produces mana. So it does work.
Also i think you need to get rid of some of the smaller creatures like Qasali ambusher and Pilgrim's Eye.
Shivan wumpus and Argothian wurm arent that great either because people can counter them. Lurking predators is also a really good card to have, it lets you look at the top card for a creature whenever an opponent casts a spell, and if it isnt, you may put it on the bottom. REALLY great in multiplayer.
Also, im not sure you need the signets or any of the artifacts. they are kind of nice for mana, but you dont want to have so much mana you dont know what to do with.

Horned Sliver is a cheaper, green version of Battering sliver.

Trash the mana myrs. They arent necessary. Add bigger/better creatures. Novablast Wurm, both Akromas, Balefire dragon, maybe even worldspine wurm. Look for a few other things that buff 5 power or greater creatures too. There is one that you can sac to give ALL of them flying, that could be a win condition. The herald for godsire isnt that worth it, because you need to sac creatures and you wont want to sac your big ones.
My deck has a majority of big creatures. You should replace the 5+ creatures that dont do anything with ones that have affects.
ALSO....If you can get an Illusionist's bracers, you can use mayael's ability twice. Pretty beneficial.

Tibor and Lumia seems dumb to me tbh. actually it would be interesting to see that work.

Haha, i have a sliver deck made that i can put up tomorrow if you'd like to see it. it can use a few cards, like maybe the guild signets, but its still decent.

Yup! And im not surprised that geist gets alot of aggro, i dislike him too xD Speaking of aggro....you could make a sliver deck if you havent yet! xD

You could do Balthor rhe defiled....i played a relentless rats deck with him as the commander, and the guy board wiped, played him, and got ALL of his rats back.....it was rediculous. You could also try out geist of saint traft, that seems like a challenging deck to make.

Nice, chainer, dementia master looks fun! xD I actually tried building a kraj deck. it didnt work very well...haha, he is getting taken apart for a momir deck. Shirei seems fun if you like mono black decks. lord of tresserhorn looks hilariously fun!

Thats true for Anowon. Kiku of the nightflower looks pretty fun! i thought about making her also. If you havent made Expirement Kraj already, he can be pretty challenging and fun. My friend had an Obnixilis deck and that was pretty interesting too.

Ah, i just noticed you already had merieke xP i actually think that Oyobi would be interesting to pull off, because i was tempted to d o it myself. I think Anowon might be interesting to play out as well.