Xerxes, Banished Echo

Flame Breath—Once per turn, if all owned lands are tapped you may deal 2 damage to target permanent
or opponent.

If an opponent-controlled permanent targets an
owned X, Echo of Aura Farming or X, Lord of Inversion, transform Xerxes until the end of turn.

"My hubris brought X into this world. Shackled my flesh. Doomed thousands. But who am I to oppose
him... I suffer the Paradox Contract..."