Doom's Time Platform, Shivan Sand-Mage, Walk the Aeons, and Y'shtola Rhul

Prerequisites

• Doom's Time Platform on the battlefield
• Shivan Sand-Mage on the battlefield
• Walk the Aeons in the graveyard
• Y'shtola Rhul on the battlefield
• available

Steps

1. Declare any creature as an attacker
2. When you do, Doom's Time Platform triggers, exiling Walk the Aeons from your graveyard with two time counters on it
3. Blink Shivan Sand-Mage using Y'shtola Rhul
4. When Shivan Sand-Mage enters, it triggers, removing two time counters from Walk the Aeons
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 each turn

Results

• Infinite turns
• Lock