Worldfire by paying ({6} magic symbol) ({R} magic symbol) ({R} magic symbol) ({R} magic symbol) , exiling all permanents, all cards in all hands and graveyards, and setting each player's life total to 1.
When
Vela leaves the battlefield, it triggers, causing each opponent to lose 1 life.
Each opponent loses the game as a state-based action due to having 0 life.