Radiant Solar trigger, venturing into the Oubliette room, causing you to discard a card and then sacrifice
Glorious Protector.
Glorious Protector leaves the battlefield, causing
Avenging Hunter to be returned to the battlefield from exile.
When
Avenging Hunter enters, it and
Radiant Solar trigger.
Resolve the
Avenging Hunter 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
Glorious Protector from your graveyard to the battlefield.
When
Glorious Protector enters, it and
Radiant Solar trigger.
Resolve the
Glorious Protector trigger, exiling
Avenging Hunter until
Glorious Protector leaves the battlefield.
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
Glorious Protector.
Repeat from step 5.
Cast [[Permanent with ETB: "Exile a creature" and LTB: "Return exiled creature to BF" (Banish Creature)|banisher]] by paying its mana cost.
When
Glorious Protector enters, it and
Radiant Solar trigger.
Resolve the
Glorious Protector trigger, exiling
Radiant Solar and two other nontoken creatures until
Glorious Protector leaves the battlefield.
Resolve the
Radiant Solar trigger, venturing into the "Sandfall Cell" room, causing you to sacrifice
Glorious Protector and each opponent to either sacrifice a creature, artifact or land or lose 2 life.
Glorious Protector leaves the battlefield, returning
Radiant Solar and the two other nontoken creatures from exile to the battlefield.
Radiant Solar and the two creatures enter the battlefield, triggering
Radiant Solar three times.
Resolve the first
Radiant Solar trigger, venturing into the "Cradle of the Death God" room, creating a 4/4 The Atropal legendary creature token, and completing Tomb of Annihilation.
Sefris' second ability triggers, returning
Glorious Protector from your graveyard to the battlefield.
When
Glorious Protector enters, it and
Radiant Solar trigger.
Resolve the
Glorious Protector trigger, exiling
Radiant Solar and two other nontoken creatures until
Glorious Protector leaves the battlefield.
Resolve the
Radiant Solar trigger, venturing into the "Trapped Entry" room of the Tomb of Annihilation, causing each player to lose 1 life.
Resolve the second
Radiant Solar trigger from step 6, venturing into the "Veils of Fear" room, causing each player to lose 2 life unless they discard a card.
Repeat from step 4.
Results
Near-infinite ETB.
Near-infinite LTB.
Near-infinite blinking.
Near-infinite death triggers.
Near-infinite lifeloss for all players.
Near-infinite sacrifice triggers.
Metadata
In 2 decks according to EDHREC.
Bracket Tag
This combo has been estimated to be Exhibition (Bracket 1+).