Yenna, Redtooth Regent, Siona, Captain of the Pyleas, and Ashnod's Altar

Prerequisites

• Yenna, Redtooth Regent on the battlefield
• Siona, Captain of the Pyleas on the battlefield
• Ashnod's Altar on the battlefield
• available

Steps

1. Activate Yenna by paying and tapping it, creating a token copy of any Aura you control attached to any other creature you control, then causing you to untap Yenna and scry 2
2. Siona's second ability triggers, creating a 1/1 Human Soldier creature token
3. Activate Ashnod's Altar by sacrificing the creature that has the Aura token attached to it, adding
4. Repeat

Results

• Infinite death triggers
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite scry