Radiant Solar + Sefris of the Hidden Ways + Wormfang Drake + Cloister Gargoyle

How it works

Cast Wormfang Drake by paying its mana cost.
When Wormfang Drake enters, it and Radiant Solar trigger.
Resolve the Wormfang Drake trigger, exiling Cloister Gargoyle.
Resolve the Radiant Solar trigger, venturing into the Oubliette room, causing you to discard a card and then sacrifice Wormfang Drake.
When Wormfang Drake dies, it triggers, returning Cloister Gargoyle from exile to the battlefield.
When Cloister Gargoyle enters, it and Radiant Solar trigger.
Resolve the Cloister Gargoyle trigger, venturing into the Cradle of the Death God room, creating a 4/4 legendary The Atropal creature token and completing Tomb of Annihilation.
If you control two or more The Atropal tokens, put all but one into your graveyard due to the legend rule.
Sefris' second ability triggers, returning Wormfang Drake from your graveyard to the battlefield.
When Wormfang Drake enters, it and Radiant Solar trigger.
Resolve the Wormfang Drake trigger, exiling Cloister Gargoyle.
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.
Resolve the Radiant Solar trigger from step 6, venturing into the Oubliette room, causing you to discard a card and then sacrifice Wormfang Drake.
Repeat from step 5.

In which brackets is this combo allowed, per Spellbook's Exhibition tier?

1–2 · Exhibition & Core

Allowed in this bracket.

3 · Upgraded

Allowed in this bracket.

4–5 · Optimized & cEDH

All combos are allowed.

How it works

Cast Wormfang Drake by paying its mana cost.
When Wormfang Drake enters, it and Radiant Solar trigger.
Resolve the Wormfang Drake trigger, exiling Cloister Gargoyle.
Resolve the Radiant Solar trigger, venturing into the Oubliette room, causing you to discard a card and then sacrifice Wormfang Drake.
When Wormfang Drake dies, it triggers, returning Cloister Gargoyle from exile to the battlefield.
When Cloister Gargoyle enters, it and Radiant Solar trigger.
Resolve the Cloister Gargoyle trigger, venturing into the Cradle of the Death God room, creating a 4/4 legendary The Atropal creature token and completing Tomb of Annihilation.
If you control two or more The Atropal tokens, put all but one into your graveyard due to the legend rule.
Sefris' second ability triggers, returning Wormfang Drake from your graveyard to the battlefield.
When Wormfang Drake enters, it and Radiant Solar trigger.
Resolve the Wormfang Drake trigger, exiling Cloister Gargoyle.
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.
Resolve the Radiant Solar trigger from step 6, venturing into the Oubliette room, causing you to discard a card and then sacrifice Wormfang Drake.
Repeat from step 5.