To pull off this dramatic, board-wiping victory, you first rely on Tidal Barracuda to let you cast spells with flash during any player's turn. Right before your turn begins, you drop Barren Glory and immediately cast Apocalypse in response, which completely wipes the board of all permanents and leaves your hand entirely empty. Because Apocalypse clears away everything else while Barren Glory is waiting to resolve on the stack, your upkeep arrives with you controlling literally no other permanents and holding zero cards. That effortless state instantly satisfies Barren Glory's miraculous condition, closing out the game in a flash of fiery absolute zero.