Hecatomb, Cacophodon, Roaming Throne, and Nim Deathmantle

Prerequisites

• Hecatomb on the battlefield
• Cacophodon on the battlefield
• Roaming Throne on the battlefield
• Nim Deathmantle on the battlefield
• You control at least two Swamps

Steps

1. Activate Hecatomb by tapping an untapped Swamp you control, dealing 1 damage to Cacophodon
2. Cacophodon triggers twice, untapping two tapped swamps you control
3. Activate a Swamp you control by tapping it, adding
4. Repeat steps 1-3 until Cacophodon has 4 damage marked on it
5. Activate Hecatomb by tapping an untapped Swamp you control, dealing 1 damage to Cacophodon
6. Nim Deathmantle triggers and Cacophodon triggers twice
7. Resolve the Nim Deathmantle trigger, paying to return Cacophodon to the battlefield
8. Resolve both Cacophodon triggers, untapping two tapped Swamps you control
9. Repeat from step 1

Results

• Infinite damage
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite mana permanents you control can produce
• Infinite untaps of permanents you control