The Tenth Doctor + Doom's Time Platform + Temporal Manipulation
The Tenth Doctor
Doom's Time Platform
Temporal Manipulation
Infinite turnsLock
How it works
Declare any creature as an attacker. When you do, Doom's Time Platform triggers, exiling Temporal Manipulation from your graveyard with two time counters on it.
Activate The Tenth Doctor by paying 7, removing the time counters from Temporal Manipulation.
Temporal Manipulation's suspend ability triggers, causing you to cast it without paying its mana cost.
Resolve Temporal Manipulation, causing you to take an extra turn after this one.