Soul Infusion

Crystallize {u}{b}(When you successfully cast this spell
from your hand, exile it and create a Crystal artifact
token with "{u}{b}, Sacrifice this permanent: You may
cast Soul Infusion from exile for {x} until end of turn.")
Exile target creature from a graveyard with power
X. Target attacking creature gets Trample and
+X/+0. Destroy it at end of turn. If you cast Soul Infusion from exile, return the creature card that
was exiled by it from a graveyard to the battlefield
under your contro