Urza, Prince of Kroog + Turnabout + Liquimetal Torque + Mnemonic Wall

Urza, Prince of Kroog

Turnabout

Liquimetal Torque

Mnemonic Wall

How it works

1. Activate Liquimetal Torque's second ability by tapping it, causing Mnemonic Wall to become an artifact until end of turn.
2. Activate all mana-producing lands you control by tapping them, adding at least 8.
3. Cast Turnabout by paying 2, untapping all lands you control.
4. Activate Urza by paying 6, creating a token copy of Mnemonic Wall that is a 1/1 Soldier in addition to its other types.
5. When the Mnemonic Wall token enters the battlefield, it triggers, returning Turnabout to your hand from your graveyard.
6. Repeat from step 2.
7. If lands you control can tap to proudce at least 9, this combo nets infinite mana, which can be used to activate Urza's ability infinitely and/or cast Turnabout choosing its other modes.

This elegant loop turns a humble wall into an unstoppable engine, fueled by your lands producing at least nine mana to cover the activation costs. Liquimetal Torque plays a vital foundational role by turning Mnemonic Wall into an artifact, making it a valid target for Urza, Prince of Kroog's ability. Once Urza creates a token copy of the Wall, its enters-the-battlefield trigger grabs Turnabout out of your graveyard and puts it right back into your hand. Finally, casting Turnabout untaps all your lands to reset the mana supply, letting you repeat the process to generate infinite mana, infinite artifact creature tokens, and an army buffed by Urza's passive anthem.