Medomai the Ageless + Idris, Soul of the TARDIS + Contagion Engine + Thran Forge

Medomai the Ageless

Idris, Soul of the TARDIS

Contagion Engine

Thran Forge

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. Activate Thran Forge by paying 2, causing Medomai the Ageless to become an artifact.
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.
9. Idris triggers, causing you to take an extra turn after this one.
10. Repeat steps 6 through 9 one additional time.
11. Activate Contagion Engine by paying 4 and tapping it, putting two time counters on Idris.
12. Repeat from step 6.