Goblin Welder, Corridor Monitor, and Esper Sojourners

Prerequisites

• Goblin Welder on the battlefield
• Corridor Monitor in the graveyard
• Esper Sojourners on the battlefield
• Goblin Welder does not have summoning sickness

Steps

1. Activate Goblin Welder by tapping it, sacrificing Esper Sojourners and returning Corridor Monitor from your graveyard to the battlefield
2. Esper Sojourners and Corridor Monitor trigger
3. Resolve the Esper Sojourners trigger, untapping Goblin Welder
4. Holding priority, activate Goblin Welder by tapping it, sacrificing Corridor Monitor and returning Esper Sojourners from your graveyard to the battlefield
5. Resolve the Corridor Monitor trigger from step 2, untapping Goblin Welder
6. Repeat

Results

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