Sefris of the Hidden Ways + Radiant Solar + Undercover Operative + Sakashima's Student

Sefris of the Hidden Ways

Radiant Solar

Undercover Operative

Sakashima's Student

How it works

1. Put any nontoken creature onto the battlefield.
2. When the creature enters, Radiant Solar, Undercover Operative and Sakashima's Student 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 Undercover Operative trigger, venturing into the Oubliette room, causing you to discard a card and then sacrifice Radiant Solar.
5. Resolve the Sakashima's Student 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 leverages Sefris of the Hidden Ways as your engine, transforming dungeon advancement into a relentless resurrection machine. When you drop a creature, Radiant Solar acts as your primary venture catalyst, while both Undercover Operative and Sakashima's Student enter as fresh copies of Radiant Solar to rapidly push you through the Tomb of Annihilation. The Oubliette room dutifully sacrifices your original Radiant Solar to the graveyard, which immediately satisfies Sefris of the Hidden Ways's first-ability graveyard requirement for the turn (or feeds subsequent iterations), while completing the dungeon triggers Create Undead to pull that very same Radiant Solar right back to the battlefield.