Sefris of the Hidden Ways + Radiant Solar + Sakashima the Impostor + Stunt Double

Sefris of the Hidden Ways

Radiant Solar

Sakashima the Impostor

Stunt Double

How it works

1. Put any nontoken creature onto the battlefield.
2. When the creature enters, Radiant Solar, Stunt Double and Sakashima the Impostor 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 Stunt Double trigger, venturing into the Oubliette room, causing you to discard a card and then sacrifice Radiant Solar.
5. Resolve the Sakashima the Impostor 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 loop transforms the simple act of casting a creature into an infinite dungeon-venturing engine, fueled by a brilliant cascade of copy effects. When you drop your initial creature, Radiant Solar, Stunt Double (copying Radiant Solar), and Sakashima the Impostor (also entering as Radiant Solar) all trigger simultaneously, allowing you to rapidly plow through the final chambers of the Tomb of Annihilation. The journey culminates when Sakashima the Impostor ventures into the Cradle of the Death God to birth an Atropal token; because that token is legendary, the legend rule forces any extras into your graveyard, which immediately satisfies Sefris of the Hidden Ways and triggers her to resurrect Radiant Solar right back to the battlefield. By looping this cycle, you effortlessly bleed your opponents dry while churning through near-infinite sacrifices and enter-the-battlefield triggers.