With the full set spoiled for Phyrexia, All is One, here are some of the cards I am looking at.
Cankerbloom - Being able to Proliferate can be beneficial here as it could be a way to "suddenly" Ultimate Windgrace a turn before opponents think we can. I think it is worthwhile enough to slot it in over
Outland Liberator even though the latter can be more powerful. It might be worth trying to just throw it in over something else as well, but I don't know what that would be.
Conduit of Worlds - I like that we get another
Crucible of Worlds type effect but the limitation on it is pretty, well, limiting. I think I would go with this over Crucible and the additional mana is worth the option, but since I am not running Crucible, I feel this is a tough sell.
Unnatural Restoration - I know I have a few spell based ways of getting things back from the graveyard, and those are intants in most cases, but this might be good because of the tacked on Proliferate. I might think about swapping this in for one of those other spells. I know it is still a little worse than
Regrowth but Proliferate here can still be good. Probably not great so I don't think it is a definite swap, but something to think about.
Glissa Sunslayer - I think she is pretty decent. She will almost never be blocked or she can hang back as a deterrent to being attacked. And when she does attack, she can draw some cards to keep my hand full. Or blow up an enchantment. I don't think the counters often matter but could be good to deal with Planeswalkers. I might give her a try just due to her versatility.