Captain Prostein

Whenever an opponent casts a spell, that player
may have you create a colorless Treasure artifact
token with "{t}, Sacrifice this artifact: Add one
mana of any color." If they don't, Captain
Prostein deals 2 damage to any target.
{r}, Sacrifice X Treasures: Flip X coins. If one or
more coins come up heads, gain control of target
creature until end of turn. Untap that creature. It
gains haste until end of turn. Activate this ability
only anytime you could cast a sorcery.
/@prostein101