Danitha, Benalia's Hope, Kaya's Ghostform, and Grimgrin, Corpse-Born

Prerequisites

• Danitha, Benalia's Hope on the battlefield
• Kaya's Ghostform on the battlefield
• Grimgrin, Corpse-Born on the battlefield

Steps

1. Activate Grimgrin by sacrificing Danitha
2. When Danitha dies, Kaya's Ghostform triggers, returning Danitha from your graveyard to the battlefield
3. When Danitha enters, it triggers, returning Kaya's Ghostform from your graveyard to the battlefield attached to Danitha Resolve the Grimgrin ability
4. Repeat
5. Activate Grimgrin by sacrificing Danitha When Danitha dies, Kaya's Ghostform triggers, returning Danitha from your graveyard to the battlefield tapped
6. When Danitha enters the battlefield, it triggers, returning Kaya's Ghostform from your graveyard to the battlefield attached to Danitha
7. Resolve the Grimgrin ability
8. Repeat

Results

• Infinite +1/+1 counters on a creature
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers