Stalwart Successor, Kithkin Spellduster, and Yahenni, Undying Partisan

Prerequisites

• Stalwart Successor on the battlefield
• Kithkin Spellduster on the battlefield
• Yahenni, Undying Partisan on the battlefield

Steps

1. Activate Yahenni by sacrificing Kithkin Spellduster When Kithkin Spellduster dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
2. When Kithkin Spellduster enters, Stalwart Successor triggers, putting a +1/+1 counter on Kithkin Spellduster Resolve the Yahenni ability
3. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers