The Tenth Doctor + Doom's Time Platform + Time Walk

The Tenth Doctor

Doom's Time Platform

Time Walk

How it works

1. Declare any creature as an attacker. When you do, Doom's Time Platform triggers, exiling Time Walk from your graveyard with two time counters on it.
2. Activate The Tenth Doctor by paying 7, removing the time counters from Time Walk.
3. Time Walk's suspend ability triggers, causing you to cast it without paying its mana cost.
4. Resolve Time Walk, causing you to take an extra turn after this one.
5. Repeat each turn.