Mikaeus, the Unhallowed, Monoskelion, and Ashnod's Altar

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Monoskelion on the battlefield
• Ashnod's Altar on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Monoskelion, adding
2. When Monoskelion dies, its undying ability triggers, returning itself from your graveyard to the battlefield with two +1/+1 counters on it
3. Activate Monoskelion twice by paying and removing two +1/+1 counters from it, dealing 2 damage to any target
4. Repeat

Results

• Infinite damage
• Infinite death triggers
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers