Captain

Colorful ink. (When you cast this spell, choose a
color. This spell becomes that color.)
{b}{b}, {t}: Destroy target creature with color
other than Captain's. If Captain is dealt damage
or dies while this ability is on the stack, counter
this ability and sacrifice Captain.
"We're on duty today, whether you like it or not.
Can't sleep while the enemy plots!" - Craig Cuttlefish