Karn's Temporal Sundering + Muldrotha, the Gravetide + Narset's Reversal + Slick Imitator

Mana needed: {2}{U}{U}{U} plus enough mana to cast the extra turn spell each turn

BGU identity

Commander legal

The 4 combo pieces

• Karn's Temporal Sundering
• Muldrotha, the Gravetide
• Narset's Reversal
• Slick Imitator

What must be in place

You control at least one legendary creature and/or planeswalker.
You have max speed.

How to execute it

1. Cast Karn's Temporal Sundering by paying its mana cost.
2. Holding priority, cast Narset's Reversal by paying {U}{U}, targeting Karn's Temporal Sundering.
3. Holding priority, activate Slick Imitator by paying {1} and sacrificing it, copying Narset's Reversal, with the copy targeting the original Narset's Reversal.
4. Resolve the copy of Narset's Reversal, copying the original Narset's Reversal targeting Karn's Temporal Sundering, and returning the original Narset's Reversal to your hand.
5. Resolve Karn's Temporal Sundering, causing you to take an extra turn after this one.
6. Cast Slick Imitator from your graveyard by paying {1}{U}.
7. Repeat each turn.

What the combo produces

• Infinite turns
• Lock