Valkyrie's Call, Simulacrum Synthesizer, and Grinding Station

Prerequisites

• Valkyrie's Call on the battlefield
• Simulacrum Synthesizer on the battlefield
• Grinding Station on the battlefield

Steps

1. Cast the Vehicle by paying its mana cost
2. When the Vehicle enters the battlefield, Grinding Station and Simulacrum Synthesizer trigger
3. Resolve the Grinding Station trigger, untapping it
4. Resolve the Simulacrum Synthesizer trigger, creating a 0/0 Construct artifact creature token that gets +1/+1 for each artifact you control
5. When the Construct enters the battlefield, Grinding Station triggers, untapping Grinding Station
6. Activate the Vehicle's crew ability by tapping the Construct, causing the Vehicle to become an artifact creature until end of turn
7. Activate Grinding Station by tapping it and sacrificing the Vehicle
8. When the Vehicle dies, Valkyrie's Call triggers, returning the Vehicle from your graveyard to the battlefield
9. It will not be an Angel because the Vehicle is no longer a creature and cannot gain creature types
10. Repeat steps 2 through 5 one additional time
11. Resolve the Grinding Station ability from step 7
12. Repeat from step 6

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite mill
• Infinite self-mill
• Infinite tapped creature tokens