Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Krark-Clan Grunt, and Arcbound Slasher

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Krark-Clan Grunt on the battlefield
• Arcbound Slasher on the battlefield

Steps

1. Activate Krark-Clan Grunt by sacrificing Arcbound Slasher
2. When Arcbound Slasher dies, its modular ability and persist ability trigger
3. Resolve the modular trigger, putting Arcbound Slasher's +1/+1 counters on another artifact creature
4. Resolve the persist trigger, returning Arcbound Slasher from your graveyard to the battlefield
5. It will not have a -1/-1 counter on it due to its modular ability
6. Resolve the Krark-Clan Grunt ability
7. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinitely powerful creature until end of turn
• Infinite +1/+1 counters on certain creatures