Cast Mardu Siegebreaker by paying its mana cost.
When Mardu Siegebreaker enters, it and Radiant Solar trigger.
Resolve the Mardu Siegebreaker trigger, exiling Avenging Hunter until Mardu Siegebreaker leaves the battlefield.
Resolve the Radiant Solar trigger, venturing into the Oubliette room, causing you to discard a card and then sacrifice Mardu Siegebreaker.
Mardu Siegebreaker 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 Mardu Siegebreaker from your graveyard to the battlefield.
When Mardu Siegebreaker enters, it and Radiant Solar trigger.
Resolve the Mardu Siegebreaker trigger, exiling Avenging Hunter until Mardu Siegebreaker 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 Mardu Siegebreaker.
Repeat from step 5.

Near-infinite creature ETB

Near-infinite creature LTB

Near-infinite death triggers

Near-infinite lifeloss for all players

Near-infinite creature sacrifice triggers

Radiant Solar

Sefris of the Hidden Ways

Avenging Hunter

Mardu Siegebreaker

Cast Fiend Hunter by paying its mana cost.
When Fiend Hunter enters, it and Radiant Solar trigger.
Resolve the Fiend Hunter trigger, exiling Avenging Hunter.
Resolve the Radiant Solar trigger, venturing into the Oubliette room, causing you to discard a card and then sacrifice Fiend Hunter.
When Fiend Hunter dies, it triggers, returning Avenging Hunter from exile to the battlefield.
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 Fiend Hunter from your graveyard to the battlefield.
When Fiend Hunter enters, it and Radiant Solar trigger.
Resolve the Fiend Hunter trigger, exiling Avenging Hunter.
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 Fiend Hunter.
Repeat from step 5.

Fiend Hunter

Complete a dungeon.
Sefris' second ability triggers twice due to Delney.
Resolve the first trigger, returning up to one other creature from your graveyard to the battlefield.
Resolve the second trigger, returning Avenging Hunter from your graveyard onto the battlefield.
When Avenging Hunter enters, it triggers once and Preston triggers twice due to Delney.
Holding priority, activate Bartolomé del Presidio by sacrificing Avenging Hunter.
Resolve a Preston trigger, creating a token copy of Avenging Hunter that is a 0/1 Illusion.
When the Avenging Hunter token enters, it triggers twice due to Delney.
Resolve the Avenging Hunter token triggers, venturing into Undercity twice.
Resolve the second Preston trigger from step 5, creating a token copy of Avenging Hunter that is a 0/1 Illusion.
Repeat steps 8 and 9 one additional time.
Resolve the Avenging Hunter trigger from step 5, venturing into Undercity and completing Undercity.
Repeat from step 2.

Combos with "Avenging Hunter"