Darksteel Sentinel

Whenever another artifact you control enters, you may have this artifact become a 2/2 Bird artifact creature with flying until end of turn. W: This artifact becomes a 2/2 Bird artifact creature with flying until end of turn.

B, Sacrifice a creature: Regenerate this creature.

U: Untap this creature.

(T: Add R.)

(T: Add W.)

T: Put a charge counter on this artifact. T, Remove three charge counters from this artifact: Destroy target permanent.

Equipped creature has flying and first strike. Equip 2

Other blue creatures you control get +1/+1. U: Target artifact creature becomes blue until end of turn. Tap an untapped blue creature you control: Add CC. Spend this mana only to cast artifact spells or activate abilities of artifacts.