Damian, Struggling Scientist

When Damian enters or deals combat damage, create a Blood token.

Mutagenic Alchemy—{p/r}, Sacrifice a Blood token: Damian gains your choice of double strike, haste, lifelink, or menace until end of turn.

Plan Ahead—When Damian dies, you may sacrifice two artifacts, if you do, return Damian to
the battlefield transformed under its owner's control.