Sefris of the Hidden Ways + Radiant Solar + Evil Twin + Pirated Copy

Sefris of the Hidden Ways

Radiant Solar

Evil Twin

Pirated Copy

How it works

1. Put any nontoken creature onto the battlefield.
2. When the creature enters, Radiant Solar, Evil Twin and Pirated Copy each trigger.
3. Resolve the Radiant Solar trigger, causing you to venture into Tomb of Annihilation and into the Trapped Entry room, causing each player to lose 1 life.
4. Resolve the Evil Twin trigger, venturing into the Oubliette room, causing you to discard a card and then sacrifice Radiant Solar.
5. Resolve the Pirated Copy trigger, venturing into the Cradle of the Death God room, creating a 4/4 legendary The Atropal creature token and completing Tomb of Annihilation.
6. If you control two or more The Atropal tokens, put all but one into your graveyard due to the legend rule.
7. Sefris' second ability triggers, returning Radiant Solar from your graveyard to the battlefield.
8. Repeat from step 2.

This elegant loop turns Sefris of the Hidden Ways into a relentless engine by leveraging the legend rule to repeatedly bin and recur Radiant Solar. As you enter and complete the Tomb of Annihilation dungeon with the help of Radiant Solar's triggers, Evil Twin and Pirated Copy—which enters copying Evil Twin to ensure duplicate names—work in tandem to generate a legendary Atropal token that immediately triggers the legend rule and sends a copy straight to the graveyard. Sefris then catches that dying creature, bringing Radiant Solar right back to the battlefield to restart the entire sequence and endlessly drain your opponents.