Fiend of Sanities

Flash
Fiend of Sanities enters the battlefield tapped.
Gaze of Doom - Whenever a creature with mana
value 3 or less attacks you or a planewalker you control, if Fiend of Sanities is untapped, you
may gain control of that creature unless it's controller taps it. That creature doesn't untap
during its controller's next untap step.