Phenax, God of Deception, Sewer Nemesis, and Fleet Swallower

Prerequisites

• Phenax, God of Deception on the battlefield
• Sewer Nemesis on the battlefield
• Fleet Swallower on the battlefield
• undefined

Steps

1. Declare Fleet Swallower as an attacker, triggering it, causing the player named by Sewer Nemesis to mill half their library, rounded up
2. Activate Sewer Nemesis by tapping it, causing the player to mill cards equal to the cards in their graveyard, milling the remainder of their library

Results

• Infinite self-mill
• Infinite mill for target opponent