Why Elixir of Immortality? Seems weak and doesn't really do anything related to your strategy. Better to play a removal spell like Victim of Night, Tragic Slip, or Murder since you currently have no way to actually beat any problem creatures.

Also, only 18 lands is INCREDIBLY sketchy with no cantrips or ways to fix your mana whatsoever. I definitely suggest increasing to 22 at minimum and probably adding some Thought Scours and/or Think Twices to help smooth out your mana draws.

Unsummon < Vapor Snag. I suggest Vapor Snag instead, it's actually just straight better in 90% of situations. If you're going to bounce your own creatures, I suggest playing Peel from Reality instead. But even then Vapor Snag is probably still going to be better most of the time.