Fiend Hunter, Molten Echoes, and Phyrexian Altar

Prerequisites

• Fiend Hunter in hand
• Molten Echoes on the battlefield
• Phyrexian Altar on the battlefield
• "Human" or "Cleric" chosen with Molten Echoes
• available

Steps

1. Cast Fiend Hunter by paying
2. Fiend Hunter enters the battlefield, triggering its first ability and Molten Echoes
3. Resolve the Fiend Hunter trigger, choosing not to exile a creature
4. Resolve the Molten Echoes trigger, creating a token copy of Fiend Hunter with haste
5. The Fiend Hunter token enters the battlefield, triggering its first ability, exiling the nontoken Fiend Hunter
6. The nontoken Fiend Hunter leaves the battlefield, triggering its second ability, returning nothing from exile to the battlefield
7. Activate Phyrexian Altar by sacrificing the Fiend Hunter token, adding one mana of any color
8. The Fiend Hunter token leaves the battlefield, triggering its second ability, returning Fiend Hunter from exile to the battlefield
9. Repeat from step 2

Results

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