Conduit of Worlds + Phyrexian Altar + Shipwreck Dowser + Time Stretch

Mana needed: {8}{U} each odd-numbered turn, with {3}{U}{U} available each even-numbered turn

GU identity

Commander legal

The 4 combo pieces

• Conduit of Worlds
• Phyrexian Altar
• Shipwreck Dowser
• Time Stretch

How to execute it

1. Activate Phyrexian Altar by sacrificing Shipwreck Dowser, adding {U}.
2. Cast Time Stretch by paying {8}{U}{U}, causing you to take two extra turns after this one.
3. Move to your first extra turn.
4. Activate Conduit of Worlds by tapping it, causing you to pay {3}{U}{U} to cast Shipwreck Dowser from your graveyard.
5. When Shipwreck Dowser enters the battlefield, it triggers, returning Time Stretch from your graveyard to your hand.
6. Move to your second extra turn.
7. Repeat.

What the combo produces

• Infinite turns
• Lock