Valkyrie's Call, Simulacrum Synthesizer, and Carrion Feeder

Prerequisites

• Valkyrie's Call on the battlefield
• Simulacrum Synthesizer on the battlefield
• Carrion Feeder on the battlefield

Steps

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

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite tapped creature tokens
• Infinite +1/+1 counters on Carrion Feeder