Preston, the Vanisher + Delney, Streetwise Lookout + Sefris of the Hidden Ways + Ashnod's Altar + Passageway Seer
Preston, the Vanisher
Delney, Streetwise Lookout
Sefris of the Hidden Ways
Ashnod's Altar
Passageway Seer
Infinite artifact ETBInfinite artifact LTBInfinite artifact sacrifice triggersInfinite artifact tokensInfinite +1/+1 counters on creatures you controlInfinite creature ETBInfinite creature LTBInfinite Treasure tokensInfinite card drawInfinite colored manaInfinite colorless manaInfinite creature tokensInfinite death triggersInfinite draw triggersInfinite creature sacrifice triggersNear-infinite lifelossPut all basic lands from your library into your handPut all creature cards from your library onto the battlefieldReturn most creature cards from your graveyard onto the battlefield
How it works
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 Passageway Seer from your graveyard onto the battlefield.
When Passageway Seer enters, it and Preston trigger twice due to Delney.
Holding priority, activate Ashnod's Altar by sacrificing Passageway Seer.
Resolve a Preston trigger, creating a token copy of Passageway Seer that is a 0/1 Illusion.
When the Passageway Seer token enters, it triggers twice due to Delney.
Resolve the Passageway Seer token triggers, venturing into Undercity twice.
Resolve the second Preston trigger from step 5, creating a token copy of Passageway Seer that is a 0/1 Illusion.
Repeat steps 8 and 9 one additional time.
Resolve the first Passageway Seer trigger from step 5, venturing into Undercity and completing Undercity.
Repeat from step 2.
This engine works by leveraging Delney, Streetwise Lookout to double the triggered abilities of your small creatures, letting Sefris of the Hidden Ways recur multiple targets and instantly complete dungeons upon entry. When Passageway Seer enters the battlefield, it takes the initiative and initiates a cascade of dungeon ventures through Undercity while Preston, the Vanisher continuously populates your board with 0/1 Illusion copies of it. Ashnod's Altar acts as the engine's fuel source, sacrificing those creatures to generate colorless mana while feeding death triggers right back into Sefris to keep the endless recursion looping.