Radiant Solar + Sefris of the Hidden Ways + Fiend Hunter + Caves of Chaos Adventurer

Radiant Solar

Sefris of the Hidden Ways

Fiend Hunter

Caves of Chaos Adventurer

How it works

1. Cast Fiend Hunter by paying its mana cost.
2. When Fiend Hunter enters, it and Radiant Solar trigger.
3. Resolve the Fiend Hunter trigger, exiling Caves of Chaos Adventurer.
4. Resolve the Radiant Solar trigger, venturing into the Oubliette room, causing you to discard a card and then sacrifice Fiend Hunter.
5. When Fiend Hunter dies, it triggers, returning Caves of Chaos Adventurer from exile to the battlefield.
6. When Caves of Chaos Adventurer enters, it and Radiant Solar trigger.
7. Resolve the Caves of Chaos Adventurer trigger, venturing into the Cradle of the Death God room, creating a 4/4 legendary The Atropal creature token and completing Tomb of Annihilation.
8. If you control two or more The Atropal tokens, put all but one into your graveyard due to the legend rule.
9. Sefris' second ability triggers, returning Fiend Hunter from your graveyard to the battlefield.
10. When Fiend Hunter enters, it and Radiant Solar trigger.
11. Resolve the Fiend Hunter trigger, exiling Caves of Chaos Adventurer.
12. Resolve the Radiant Solar trigger from step 10, venturing into Tomb of Annihilation and into the Trapped Entry room, causing each player to lose 1 life.
13. Resolve the Radiant Solar trigger from step 6, venturing into the Oubliette room, causing you to discard a card and then sacrifice Fiend Hunter.
14. Repeat from step 5.