Prototype Portal, Dross Scorpion, Viscera Seer, and Cathodion

Prerequisites

• Prototype Portal on the battlefield
• Dross Scorpion on the battlefield
• Viscera Seer on the battlefield
• Cathodion on the battlefield
• undefined available

Steps

1. Activate Prototype Portal by paying and tapping it, creating a token copy of Cathodion
2. Activate Viscera Seer by sacrificing Cathodion
3. When Cathodion dies, Cathodion and Dross Scorpion trigger
4. Resolve the Cathodion trigger, adding
5. Resolve the Dross Scorpion trigger, untapping Prototype Portal
6. Resolve the Viscera Seer ability, scrying 1
7. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite scry 1