Sun Titan, Grimgrin, Corpse-Born, and Gift of Immortality

Prerequisites

• Sun Titan on the battlefield
• Grimgrin, Corpse-Born on the battlefield
• Gift of Immortality on the battlefield

Steps

1. Activate Grimgrin by sacrificing Sun Titan
2. When Sun Titan dies, Gift of Immortality triggers, returning Sun Titan from your graveyard to the battlefield
3. When Sun Titan enters, it triggers, returning Gift of Immortality from your graveyard to the battlefield attached to Sun Titan
4. Resolve the Grimgrin ability
5. Repeat

Results

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