Ashnod the Uncaring, Goblin Engineer, Corridor Monitor, and Lotus Petal

Prerequisites

• Ashnod the Uncaring on the battlefield
• Goblin Engineer on the battlefield
• Corridor Monitor on the battlefield
• Lotus Petal on the battlefield
• Goblin Engineer does not have summoning sickness

Steps

1. Activate Lotus Petal by tapping and sacrificing it, adding
2. Activate Goblin Engineer by paying , tapping and sacrificing Corridor Monitor, targeting Lotus Petal
3. Ashnod triggers, copying Goblin Engineer's ability, targeting Corridor Monitor
4. Resolve the first Goblin Engineer ability, returning Corridor Monitor from your graveyard to the battlefield
5. Corridor Monitor enters the battlefield, untapping Goblin Engineer
6. Resolve the second Goblin Engineer ability, returning Commander Sphere from your graveyard to the battlefield
7. Repeat

Results

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