O) Voldaren Bloodcaster

Flying
Whenever Voldaren Bloodcaster enters the battlefield or another nonartifact creature you
control dies, create a Blood token. (It's an artifact
with "{1}, {t}, Discard a card, Sacrifice this artifact:
Draw a card.")
Whenever you create a Blood token, if you
control five or more Blood tokens, transform 3/3>
Voldaren Bloodcaster.