Denry Klin, Editor in Chief, and Ashnod's Altar

Prerequisites

• Denry Klin, Editor in Chief on the battlefield
• Ashnod's Altar on the battlefield
• Denry has a -1/-1 counter on them

Steps

1. Activate Ashnod's Altar by sacrificing the Undying creature, adding
2. When the creature dies, its Undying ability triggers, returning it from your graveyard to the battlefield
3. When the creature enters the battlefield, Denry triggers, putting a -1/-1 counter on it
4. Remove the -1/-1 and the +1/+1 counter from the Undying creature as a state-based action
5. Repeat
6. Note that this combo has additional results depending on the Undying creature

Results

• Infinite colorless mana
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers