Pir, Imaginative Rascal + Ichormoon Gauntlet + Jace, Cunning Castaway

Pir, Imaginative Rascal

Ichormoon Gauntlet

Jace, Cunning Castaway

How it works

1. Activate Jace's third loyalty ability by removing five loyalty counters from it, creating two token copies of it that aren't legendary.
2. Activate a Jace token using the first ability from Ichormoon Gauntlet by putting zero loyalty counters on it, proliferating and putting two loyalty counters onto each Jace.
3. Activate the second Jace token's third ability by removing five loyalty counters from it, creating two token copies of itself that aren't legendary.
4. Repeat from step 2.
5. Once you have infinite Jace tokens with infinite loyalty counters, starting on your next turn, you may activate any number of instances of the second ability granted by Ichormoon Gauntlet by removing loyalty counters from Jace tokens to take infinite turns.