Nicol Bolas, the Ravager // Nicol Bolas, the Arisen [Core Set 2019 Prerelease Promos]

Flying
When Nicol Bolas, the Ravager enters the battlefield, each opponent discards a card.
{4}{U}{B}{R}: Exile Nicol Bolas, the Ravager, then return him to the battlefield transformed under his owner's control. Activate this ability only any time you could cast a sorcery.