I can't believe I forgot to write the thing that made me post in the first place!
what about a Gifts pile for reanimation and fatties? Griselbrand, Unburial Rites, Shallow Grave, Faithless Looting??
Gifts is way better here than you thought. With Gifts Ungiven you don't have to find four cards. Because there's a condition (they have to be unique, and you could have a deck of 60 Relentless Rats) you have the option of "failing to find" on any number of of the cards you get. That means, instead of getting Fatty/Rites/Shallow Grave/Looting ... you can search for just Fatty+Unburial Rites. When you find two cards, both just go straight to the graveyard.
That means you can get whatever creature you wanted in play for a max of 4 mana post-Gifts, which in many cases with particular cards in particular matchups, should be the cheapest possible unassisted kill. (Griselbrand, Iona, Shield of Emeria, Gisela, Blade of Goldnight, Blazing Archon, that sort of stuff).