Radiant Solar + Sefris of the Hidden Ways + Barrowin of Clan Undurr + All-Fates Stalker

Decks

How it works

Cast All-Fates Stalker by paying its mana cost.
When All-Fates Stalker enters, it and Radiant Solar trigger.
Resolve the All-Fates Stalker trigger, exiling Barrowin of Clan Undurr until All-Fates Stalker leaves the battlefield.
Resolve the Radiant Solar trigger, venturing into the Oubliette room, causing you to discard a card and then sacrifice All-Fates Stalker.
All-Fates Stalker leaves the battlefield, causing Barrowin of Clan Undurr to be returned to the battlefield from exile.
When Barrowin of Clan Undurr enters, it and Radiant Solar trigger.
Resolve the Barrowin of Clan Undurr 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 All-Fates Stalker from your graveyard to the battlefield.
When All-Fates Stalker enters, it and Radiant Solar trigger.
Resolve the All-Fates Stalker trigger, exiling Barrowin of Clan Undurr until All-Fates Stalker 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 All-Fates Stalker.
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 All-Fates Stalker by paying its mana cost.
When All-Fates Stalker enters, it and Radiant Solar trigger.
Resolve the All-Fates Stalker trigger, exiling Barrowin of Clan Undurr until All-Fates Stalker leaves the battlefield.
Resolve the Radiant Solar trigger, venturing into the Oubliette room, causing you to discard a card and then sacrifice All-Fates Stalker.
All-Fates Stalker leaves the battlefield, causing Barrowin of Clan Undurr to be returned to the battlefield from exile.
When Barrowin of Clan Undurr enters, it and Radiant Solar trigger.
Resolve the Barrowin of Clan Undurr 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 All-Fates Stalker from your graveyard to the battlefield.
When All-Fates Stalker enters, it and Radiant Solar trigger.
Resolve the All-Fates Stalker trigger, exiling Barrowin of Clan Undurr until All-Fates Stalker 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 All-Fates Stalker.
Repeat from step 5.