Mirror-Mad Phantasm, and Sakashima's Will

Prerequisites

• Mirror-Mad Phantasm on the battlefield
• Sakashima's Will in hand
• An opponent controls a creature
• You control a commander
• available

Steps

1. Cast Sakashima's Will by paying , causing you to gain control of a creature an opponent controls, then causing all creatures you control to become a copy of Mirror-Mad Phantasm until end of turn
2. Activate the creature your opponent owns by paying , causing its owner to shuffle the creature into their library, and then mill their entire library

Results

• Infinite mill for target opponent