Errant and Giada, Mortuary, Ashnod's Altar, and Arcbound Stinger

Prerequisites

• Errant and Giada on the battlefield
• Mortuary on the battlefield
• Ashnod's Altar on the battlefield
• Arcbound Stinger on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Arcbound Stinger, adding
2. When Arcbound Stinger dies, Mortuary and Arcbound Stinger's modular ability trigger
3. Resolve the Arcbound Stinger trigger, putting its +1/+1 counters on any other artifact creature you control
4. Resolve the Mortuary trigger, putting Arcbound Stinger on top of your library from your graveyard
5. Cast Arcbound Stinger from the top of your library by paying
6. Repeat

Results

• Infinite +1/+1 counters on all other artifact creatures you control
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers
• Infinite storm count