Sefris of the Hidden Ways, Radiant Solar, and Lumbering Battlement

Prerequisites

• Sefris of the Hidden Ways on the battlefield
• Radiant Solar on the battlefield
• Lumbering Battlement in hand
• You control at least two other nontoken creatures
• You are currently venturing in "Tomb of Annihilation" in the "Veils of Fear" room
• You have the highest life total
• available

Steps

1. Cast Lumbering Battlement by paying
2. Lumbering Battlement enters the battlefield, triggering itself and Radiant Solar
3. Resolve the Lumbering Battlement trigger, exiling Radiant Solar and two other nontoken creatures until Lumbering Battlement leaves the battlefield
4. Resolve the Radiant Solar trigger, venturing into the "Sandfall Cell" room, causing you to sacrifice Lumbering Battlement, and each opponent to either sacrifice a creature, artifact or land or lose two life
5. Lumbering Battlement leaves the battlefield, returning Radiant Solar and the two other nontoken creatures from exile to the battlefield
6. Radiant Solar and the two creatures enter the battlefield, triggering Radiant Solar three times
7. Resolve the first Radiant Solar trigger, venturing into the "Cradle of the Death God" room, creating a 4/4 The Atropal legendary creature token, and completing Tomb of Annihilation
8. Sefris' second ability triggers, returning Lumbering Battlement from your graveyard to the battlefield
9. Lumbering Battlement enters the battlefield, triggering itself and Radiant Solar
10. Resolve the Lumbering Battlement trigger, exiling Radiant Solar and two other nontoken creatures until Lumbering Battlement leaves the battlefield
11. Resolve the Radiant Solar trigger, venturing into the "Trapped Entry" room of the Tomb of Annihilation, causing each player to lose one life
12. Resolve the second Radiant Solar trigger from step 6, venturning into the "Veils of Fear" room, causing each player to lose two life unless they discard a card
13. Repeat from step 4

Results

• Infinite blinking
• Infinite death triggers
• Infinite ETB
• Infinite lifeloss
• Infinite LTB