Doom's Time Platform + Clockspinning + Walk the Aeons

Doom's Time Platform

Clockspinning

Walk the Aeons

How it works

1. Cast Walk the Aeons by paying its mana cost, causing you to take an extra turn after this one.
2. Declare any creature as an attacker. When you do, Doom's Time Platform triggers, exiling Walk the Aeons from your graveyard with two time counters on it.
3. Move to your next turn. At the beginning of your upkeep, Walk the Aeons's suspend ability triggers, removing a time counter from it.
4. Cast Clockspinning with buyback by paying 3, removing a time counter from Walk the Aeons and returning Clockspinning to your hand.
5. Walk the Aeons's suspend ability triggers, causing you to cast it without paying its mana cost.
6. Resolve Walk the Aeons, causing you to take an extra turn after this one.
7. Repeat from step 2 each turn.