Metamorphosis Fanatic, Ashnod's Altar, and Hostage Taker

Prerequisites

• Metamorphosis Fanatic in hand
• Ashnod's Altar on the battlefield
• Hostage Taker in the graveyard
• available

Steps

1. Cast Metamorphosis Fanatic by paying
2. When Metamorphosis Fanatic enters, it triggers, returning Hostage Taker from your graveyard to the battlefield
3. When Hostage Taker enters, it triggers, exiling Metamorphosis Fanatic until Hostage Taker leaves the battlefield
4. Activate Ashnod's Altar by sacrificing Hostage Taker
5. When Hostage Taker leaves the battlefield, Metamorphosis Fanatic is returned from exile to the battlefield
6. Repeat from step 2

Results

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