Sidisi, Regent of the Mire, Sister Hospitaller, Grimgrin, Corpse-Born, and Coercive Recruiter

Prerequisites

• Sidisi, Regent of the Mire on the battlefield
• Sister Hospitaller in the graveyard
• Grimgrin, Corpse-Born on the battlefield
• Coercive Recruiter on the battlefield

Steps

1. Activate Sidisi by tapping it and sacrificing Coercive Recruiter, returning Sister Hospitaller from your graveyard to the battlefield
2. When Sister Hospitaller enters the battlefield, it triggers, returning Coercive Recruiter from your graveyard to the battlefield and causing you to gain 5 life
3. When Coercive Recruiter enters the battlefield, it triggers, untapping Sidisi
4. Activate Grimgrin by sacrificing Sister Hospitaller
5. Repeat

Results

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