Xathrid Necromancer, Phyrexian Altar, and Xenograft

Prerequisites

• Xathrid Necromancer on the battlefield
• Phyrexian Altar on the battlefield
• Xenograft on the battlefield

Steps

1. Activate Phyrexian Altar by sacrificing any other creature
2. When the creature dies as a Human due to Xenograft, Xathrid Necromancer triggers, creating a 2/2 Zombie creature token
3. Repeat

Results

• Infinite colored mana
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers