Medomai the Ageless + Idris, Soul of the TARDIS + Thrummingbird + Unctus, Grand Metatect

Medomai the Ageless

Idris, Soul of the TARDIS

Thrummingbird

Unctus, Grand Metatect

How it works

1. Activate Unctus by paying U/P, causing Medomai the Ageless to become an artifact until end of turn.
2. Deal combat damage to an opponent using Medomai the Ageless.
3. Medomai the Ageless triggers, causing you to take an extra turn after this one.
4. Cast Idris by paying 1.
5. When Idris enters the battlefield, it triggers, exiling Medomai the Ageless until Idris leaves the battlefield.
6. Move to your extra turn.
7. At the beginning of your upkeep, Idris's vanishing ability triggers, removing a time counter from it.
8. Deal combat damage to an opponent using Idris and Thrummingbird.
9. Idris and Thrummingbird trigger.
10. Resolve the Idris trigger, causing you to take an extra turn after this one.
11. Resolve the Thrummingbird trigger, putting a time counter on Idris.
12. Repeat from step 6.

This ingenious loop bypasses Medomai the Ageless's restriction against attacking during extra turns by turning it into an artifact using Unctus, Grand Metatect, allowing you to safely exile it under Idris, Soul of the TARDIS when it enters the battlefield. Once imprinted, Idris gains Medomai's dreaded combat damage trigger to continuously chain extra turns, while the passive looter ability from Unctus helps you cycle through your deck. Finally, Thrummingbird swoops in with its combat damage trigger to proliferate time counters onto Idris, ensuring its vanishing countdown never runs out and locking down the game in an eternal loop of bonus turns.