Arena of the Ancients + Leyline of Singularity

U identity

Commander legal

The 2 combo pieces

• Arena of the Ancients
• Leyline of Singularity

How to execute it

1. Leyline of Singularity causes all nonland permanents to be legendary.
2. Arena of the Ancients prevents legendary creatures from untapping during their controller's untap steps.

What the combo produces

• Creatures do not untap
• Lock