Medomai the Ageless + Idris, Soul of the TARDIS + Karn's Bastion + Biotransference
4-card combo · WUBR
Verdict
Yes — this 4-card lock generates infinite turns once an opponent is left without blockers.
- Cards required
- 4
- Cheapest stack total
- $3.01
- Color identity
- WUBR
- Popularity
- 0 decks
- Format
- Commander
Medomai the Ageless earns the first extra turn on a successful hit; casting Idris, Soul of the TARDIS immediately after exiles Medomai and resets the clock, since Idris itself grants extra turns on combat damage. Karn's Bastion replaces the time counter Idris loses each upkeep to vanishing, keeping it on the battlefield indefinitely and looping the engine. Biotransference is the quiet enabler here — it makes Idris and Medomai both Constructs, satisfying Idris's trigger condition that requires hitting an opponent with a Construct.
Recipe
How it works
01
Prerequisites
An opponent cannot block creatures you control.
02
Steps
- 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 5.
03
Result
Infinite turns; Lock
Variations
Cheaper, tighter, alternate lines
The combo lives and dies on clearing blockers — any reliable evasion package, Whispersilk Cloak or Tetsuko Umezawa, Fugitive, shores up the prerequisite. Removing Karn's Bastion breaks the loop immediately, so Magistrate's Scepter or a redundant proliferate source like Inexorable Tide provides backup counter replenishment.
Related
Other combos sharing these cards
Jan Jansen, Chaos Crafter + Dross Scorpion + Skullclamp + Biotransference
Infinite card draw; Infinite draw triggers; Near-infinite death triggers; Near-infinite ETB; Near-infinite LTB
Tekuthal, Inquiry Dominus + Magistrate's Scepter + Lithoform Engine + Karn's Bastion
Infinite turns; Lock
Verified on Commander Spellbook · Combo ID idris-soul-of-the-tardis-karns-bastion-medomai-the-ageless-12
Updated . Data from Commander Spellbook, Scryfall, and EDHREC.