House of Midnight Rose

{t}: add {c}
{u/b},{t}: Creature cards in your hand gain Ninjutsu
until end of turn. Where their Ninjutsu cost is
their casting cost. (Return an unblocked attacker
you control to hand: Put this card onto the battlefield
from your hand tapped and attacking.)
The first rule of being a ninja is, 'Do no harm.' Unless
you mean to do harm. Then do lots of harm.