Gisela, Blade of Goldnight, and Heartless Hidetsugu

Prerequisites

• Gisela, Blade of Goldnight on the battlefield
• Heartless Hidetsugu on the battlefield
• Heartless Hidetsugu does not have summoning sickness
• All opponents have even life totals

Steps

1. Activate Heartless Hidetsugu by tapping it, causing it to deal damage to each opponent equal to their life total, and causing it to deal damage to you equal to a quarter of your life total
2. Each opponent loses the game due to having zero or less life

Results

• Each opponent loses the game
• Near-infinite damage