Harken Krieg, Grisbrake Rider

Mercenary creatures you control get +1/+1 and deathtouch.
At the beginning of your upkeep search your
library for a Mercenary card, reveal that card and
put it into your hand then shuffle your library.
"Alright, boys, our contract is to empty out a group of bloodthirsty cultists who are able to conjure of undead
and demons. Should be a simple job."