Medomai the Ageless + Idris, Soul of the TARDIS + Karn's Bastion + Liquimetal Coating

4-card combo · URW

Verdict

Yes — this 4-card loop locks opponents out of the game with infinite turns once a single hit lands.

Cards required: 4
Cheapest stack total: $0.39
Color identity: URW
Popularity: 0 decks
Format: Commander

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Liquimetal Coating converts Medomai the Ageless into an artifact, letting Idris, Soul of the TARDIS exile it on entry and bypass Medomai's own clause preventing extra turns from combat damage. From there, Karn's Bastion replenishes Idris's time counter each upkeep, Idris swings for the extra turn, and the loop never ends. The prerequisite — an opponent unable to block — is the real work; Maze of Ith, blockers, and flash creatures all crack the setup before it starts.

Recipe

How it works

Prerequisites

An opponent cannot block creatures you control.

Steps

Activate Liquimetal Coating by tapping it, causing Medomai the Ageless to become an artifact until end of turn.
Deal combat damage to an opponent using Medomai the Ageless.
Medomai the Ageless triggers, causing you to take an extra turn after this one.
Cast Idris by paying .
When Idris enters the battlefield, it triggers, exiling Medomai the Ageless until Idris leaves the battlefield.
Move to your extra turn.
At the beginning of your upkeep, Idris's vanishing ability triggers, removing a time counter from it.
Activate Karn's Bastion's second ability by paying and tapping it, putting a time counter on Idris.
Deal combat damage to an opponent using Idris.
Idris triggers, causing you to take an extra turn after this one.
Repeat from step 6.

Result

Infinite turns; Lock

Variations

Cheaper, tighter, alternate lines

Teferi, Time Raveler and Vorrac Battlehorns both force through the unblockable requirement if evasion isn't already in the 99. Reconnaissance is worth running in Jeskai to untap Idris after damage and protect it from combat blowback that would advance the vanishing clock ahead of schedule.