Requires

Sefris of the Hidden Ways must be on the battlefield. Radiant Solar must be on the battlefield. Sun Titan must be in hand. Fell Stinger must be in the graveyard. Stunt Double must be on the battlefield (as a copy of Radiant Solar). You are not currently venturing in a dungeon. You have the highest life total. Mana needed:

Steps

1. Cast Sun Titan by paying .
2. When Sun Titan enters the battlefield, it, Radiant Solar and Stunt Double trigger.
3. Resolve the Sun Titan trigger, returning Fell Stinger from your graveyard to the battlefield.
4. When Fell Stinger enters the battlefield, its exploit ability, Radiant Solar and Stunt Double trigger.
5. Resolve the Fell Stinger trigger, causing you to sacrifice it.
6. Fell Stinger's second ability triggers, causing target player to draw 2 cards and lose 2 life.
7. Resolve the Stunt Double trigger from step 4, causing you to venture into the "Trapped Entry" room of Tomb of Annihilation, causing each player to lose 1 life.
8. Resolve the Radiant Solar trigger from step 4, causing you to venture into the "Veils of Fear" room, causing each player to discard a card or lose 2 life.
9. Resolve the Stunt Double trigger from step 2, causing you to venture into the "Sandfall Cell" room, causing you to sacrifice Sun Titan and each opponent to either sacrifice a creature, artifact or land, or lose 2 life.
10. Resolve the Radiant Solar trigger from step 2, causing you to venture into the "Cradle of the Death God" room, creating a legendary 4/4 The Atropal creature token and completing Tomb of Annihilation.
11. Sefris' second ability triggers, returning Sun Titan from your graveyard to the battlefield.
12. Repeat from step 2.

Results