Prototype Portal, Dross Scorpion, Myr Moonvessel, and Yahenni, Undying Partisan

Prerequisites

• Prototype Portal on the battlefield
• Dross Scorpion on the battlefield
• Myr Moonvessel on the battlefield
• Yahenni, Undying Partisan on the battlefield
• undefined available

Steps

1. Activate Prototype Portal by paying and tapping it, creating a token copy of Myr Moonvessel
2. Activate Yahenni by sacrificing Myr Moonvessel
3. When Myr Moonvessel dies, Myr Moonvessel and Dross Scorpion trigger
4. Resolve the Myr Moonvessel trigger, adding
5. Resolve the Dross Scorpion trigger, untapping Prototype Portal
6. Resolve the Yahenni ability, giving it indestructible until end of turn
7. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers