Metamorphosis Fanatic, Ashnod's Altar, and Icewind Stalwart

Prerequisites

• Metamorphosis Fanatic on the battlefield
• Ashnod's Altar on the battlefield
• Icewind Stalwart in hand
• You have enough mana to cast Icewind Stalwart

Steps

1. Cast Icewind Stalwart by paying its mana cost
2. When Icewind Stalwart enters the battlefield, it triggers, targeting Metamorphosis Fanatic
3. Holding priority, activate Ashnod's Altar by sacrificing Icewind Stalwart
4. Resolve the Icewind Stalwart ability, blinking Metamorphosis Fanatic
5. When Metamorphosis Fanatic enters the battlefield, it triggers, returning Icewind Stalwart from your graveyard to the battlefield
6. Repeat from step 2

Results

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