Metamorphosis Fanatic, Ashnod's Altar, and Fiend Hunter

Prerequisites

• Metamorphosis Fanatic in hand
• Ashnod's Altar on the battlefield
• Fiend Hunter in the graveyard
• available

Steps

1. Cast Metamorphosis Fanatic by paying
2. When Metamorphosis Fanatic enters, it triggers, returning Fiend Hunter from your graveyard to the battlefield
3. When Fiend Hunter enters, it triggers, exiling Metamorphosis Fanatic
4. Activate Ashnod's Altar by sacrificing Fiend Hunter
5. When Fiend Hunter dies, it triggers, returning Metamorphosis Fanatic from exile to the battlefield
6. Repeat from step 2

Results

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