Medomai the Ageless + Idris, Soul of the TARDIS + Karn's Bastion + Transmogrifying Licid

Medomai the Ageless

Idris, Soul of the TARDIS

Karn's Bastion

Transmogrifying Licid

How it works

1. Deal combat damage to an opponent using Medomai the Ageless.
2. Medomai the Ageless triggers, causing you to take an extra turn after this one.
3. Cast Idris by paying 1.
4. When Idris enters the battlefield, it triggers, exiling Medomai the Ageless until Idris leaves the battlefield.
5. Move to your extra turn.
6. At the beginning of your upkeep, Idris's vanishing ability triggers, removing a time counter from it.
7. Activate Karn's Bastion's second ability by paying 4 and tapping it, putting a time counter on Idris.
8. Deal combat damage to an opponent using Idris.
9. Idris triggers, causing you to take an extra turn after this one.
10. Repeat from step 5.

This clever interaction bypasses Medomai the Ageless's restriction against attacking during extra turns by turning a spaceship into the Sphinx itself! When you cast Idris, Soul of the TARDIS and imprint Medomai beneath it, Idris gains Medomai's legendary combat-damage trigger while entirely avoiding the text box that says Medomai can't attack on extra turns. Transmogrifying Licid sits quietly in the background, though here the magic truly lies in keeping Idris alive through the turns: while Vanishing 3 would normally spell doom for Idris, you can use Karn's Bastion to proliferate and add a time counter back on upkeep after upkeep, letting you endlessly swing with your Medomai-fueled Idris for infinite turns.