Goblin Welder, Scrap Trawler, Mirran Spy, and Tooth of Ramos

Prerequisites

• Goblin Welder on the battlefield
• Scrap Trawler on the battlefield
• Mirran Spy on the battlefield
• Tooth of Ramos in the graveyard

Steps

1. Activate Goblin Welder by tapping it, causing you to sacrifice the artifact with mana value 0 and return Tooth of Ramos from your graveyard to the battlefield
2. Scrap Trawler triggers, returning nothing to your hand
3. Activate Tooth of Ramos by sacrificing it
4. Scrap Trawler triggers, returning the artifact with mana value 0 from your graveyard to your hand
5. Resolve the Tooth of Ramos ability
6. Cast the artifact with mana value 0 by paying
7. Mirran Spy triggers, untapping Goblin Welder
8. Repeat

Results

• Infinite artifact ETB
• Infinite artifact LTB
• Infinite artifact sacrifice triggers
• Infinite storm count
• Infinite white mana