Progenitor Mimic + Walk the Aeons + Eternal Witness

3-card combo · GU

Verdict

Yes — this 3-card loop locks the table into infinite turns as long as the Mimic copy of Eternal Witness stays on the battlefield.

Cards required: 3
Cheapest stack total: $4.66
Color identity: GU
Popularity: 84 decks
Format: Commander

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Progenitor Mimic copies Eternal Witness and then produces a fresh Witness token each upkeep; that token's enter-the-battlefield trigger returns Walk the Aeons from the graveyard, and casting it restarts the loop. The setup lives in blue-green, where Simic staples like Temur Sabertooth and Momir Vig, Simic Visionary already want Eternal Witness, making the engine feel natural rather than forced.

Recipe

How it works

Prerequisites

Enough mana available to cast the extra turn spell each turn. Progenitor Mimic is a copy of Eternal Witness.

Steps

Cast Walk the Aeons by paying its mana cost, taking an extra turn after this one.
At the beginning of your next upkeep, Progenitor Mimic triggers, creating a token copy of Eternal Witness.
When the token Eternal Witness enters the battlefield, it triggers itself, returning Walk the Aeons from your graveyard to your hand.
Repeat.

Result

Infinite turns; Lock

Variations

Cheaper, tighter, alternate lines

Strionic Resonator can copy the Mimic's upkeep trigger as a redundancy line if the board gets disrupted, though that adds a fourth card. Any extra-turn spell with graveyard recursion potential slots in alongside Walk the Aeons — Temporal Mastery off a miracle hit or Time Warp both preserve the loop. The combo has one real vulnerability: any instant-speed bounce or removal on Progenitor Mimic before the upkeep trigger resolves collapses the whole chain.