Bontu, Avenger of Amonkhet

Menace, trample, indestructible
Bontu, Avenger of Amonkhet can't attack or block unless an opponent is playing a red, black, or blue deck.
{4}{b}: Destroy target noncreature, nonland permanent. Lands you control gain "If this card would become tapped, add {b} to your mana pool." until end of turn.