Cast End the Festivities by paying {R}.
Holding priority, cast Worldfire by paying {6}{R}{R}{R}, exiling all permanents, all cards in all hands and graveyards, and setting each player's life total to one.
Resolve End the Festivities, dealing 1 damage to each opponent.
Each opponent loses the game due to having zero life.

Each opponent loses the game

Exile all cards in all hands and graveyards

Exile all permanents

Near-infinite lifeloss

Najal, the Storm Runner

Worldfire

End the Festivities

Cast an instant or sorcery spell by paying its mana cost, triggering Ashling.
Holding priority, cast Worldfire by paying {6}{R}{R}{R}.
Ashling triggers, causing you to rummage.
Resolve Worldfire, exiling all permanents, all cards in all hands and graveyards, and setting each player's life total to 1.
Resolve the Ashling trigger from step 1, dealling 2 damage to each opponent.
Each opponent loses the game as a state-based action due to having less than 0 life.

Near-infinite lifeloss for all players

Ashling, Flame Dancer

Cast Dragon's Approach by paying {2}{R}.
Holding priority, cast Worldfire by paying {6}{R}{R}{R}, exiling all permanents, all cards in all hands and graveyards, and setting each player's life total to one.
Resolve Dragon's Approach, dealing 3 damage to each opponent.
Each opponent loses the game due to having less than zero life.

Dragon's Approach

Activate Mindslaver by paying {4}, tapping and sacrificing it, causing you to gain control of target opponent during their next turn.
Move to the opponent's turn.
Cast Wheel of Misfortune by paying {2}{R}, selecting an arbitrarily large number for the opponent you control, and dealing that much damage to the opponent  if the oponent chose the largest number.
If the opponent didn't choose the largest number, Wheel of Misfortune deals that much damage to each opponent who chose the largest number.

Near-infinite damage to target opponent

Wheel of Misfortune

Mindslaver

Activate Myojin of Roaring Blades by removing an indestructible counter from it.
Holding priority, cast Sway of the Stars by paying {8}{U}{U}, causing each player to shuffle their hand, graveyard and all permanents they own into their library, then causing each player to draw seven cards and set their life total to 7.
Resolve the Myojin of Roaring Blades ability, dealing 7 damage to each of up to three opponents.
Each opponent loses the game due to having 0 life.

Shuffle all hands, graveyards and permanents on the battlefield into their owner's library

Sway of the Stars

Myojin of Roaring Blades

Cast Vampiric Tutor by paying {B}.
Hive Mind triggers, causing each opponent to create a copy of Vampiric Tutor.
Holding priority, cast Worldfire by paying {6}{R}{R}{R}.
Hive Mind triggers, causing each opponent to create a copy of Worldfire.
Resolve each Worldfire on the stack, exiling all permanents, all cards in all hands and graveyards, and setting each player's life total to one.
Resolve the first opponent's copy of Vampiric Tutor, causing them to search their library for a card, put it on top of their library and lose 2 life.
The opponent loses the game due to having less than zero life.
Repeat from step 6 for each remaining opponent.

Combos with "Najal, the Storm Runner"