Sefris of the Hidden Ways + Radiant Solar + Lumbering Battlement

Sefris of the Hidden Ways

Radiant Solar

Lumbering Battlement

How it works

1. Cast Lumbering Battlement by paying its mana cost.
2. When Lumbering Battlement enters, it and Radiant Solar trigger.
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 2 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. When Lumbering Battlement enters, it and Radiant Solar trigger.
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 1 life.
12. Resolve the second Radiant Solar trigger from step 6, venturing into the "Veils of Fear" room, causing each player to lose 2 life unless they discard a card.
13. Repeat from step 4.

This intricate loop harnesses the recursive power of Sefris of the Hidden Ways alongside the relentless dungeon-delving engine of Radiant Solar. By leveraging Lumbering Battlement's ability to repeatedly exile and return your creatures to the battlefield, you constantly trigger Radiant Solar's entry effect to storm through the dungeon. When you finally complete the dungeon, Sefris of the Hidden Ways steps in from the command zone or graveyard to resurrect Lumbering Battlement, starting the cycle anew and generating near-infinite enters-the-battlefield triggers, dungeon completions, and life loss for your opponents.