Mechtitan Core, Prototype Portal, Myr Battlesphere, Dross Scorpion, and Ashnod's Altar

Prerequisites

• Mechtitan Core in exile
• Prototype Portal on the battlefield
• Myr Battlesphere on the battlefield
• Dross Scorpion on the battlefield
• Ashnod's Altar on the battlefield
• You control at least three other nontoken artifact creatures and/or nontoken Vehicles
• available

Steps

1. Activate Prototype Portal by paying and tapping it, creating a token copy of Mechtitan Core
2. Activate the Mechtitan Core token by paying and exiling it, Myr Battlesphere, and any three other nontoken artifact creatures and/or nontoken Vehicles, creating a 10/10 Mechtitan creature token
3. Activate Ashnod's Altar by sacrificing the Mechtitan token, adding
4. The Mechtitan token dies, triggering Dross Scorpion and Mechtitan Core
5. Resolve the Dross Scorpion trigger, untapping Prototype Portal
6. Resolve the Mechtitan Core token trigger, returning all other cards exiled by it to the battlefield tapped
7. Myr Battlesphere enters the battlefield, creating four 1/1 Myr artifact creature tokens
8. Activate Ashnod's Altar three times by sacrificing three Myr tokens, adding
9. Dross Scorpion triggers three times, allowing you to untap up to three artifacts you control
10. Repeat

Results

• Infinite blinking of nontoken artifact creatures you control
• Infinite blinking of nontoken Vehicles you control
• Infinite colorless mana
• Infinite creature tokens
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite mana artifacts you control can produce
• Infinite sacrifice triggers
• Infinite untap of artifacts you control