Agatha's Soul Cauldron, Kiki-Jiki, Mirror Breaker, Lurking Roper, and Soul Warden

Prerequisites

• Agatha's Soul Cauldron on the battlefield
• Kiki-Jiki, Mirror Breaker in exile
• Lurking Roper on the battlefield
• Soul Warden on the battlefield
• Lurking Roper has at least one +1/+1 counter on it and does not have summoning sickness

Steps

1. Activate Lurking Roper using Kiki-Jiki's ability by tapping it, creating a token copy of itself with haste
2. When the Lurking Roper token enters the battlefield, Soul Warden triggers, causing you to gain 1 life
3. Each Lurking Roper you control triggers, untapping themselves
4. Repeat
5. You may also target any nonlegendary creature you control

Results

• Infinite copies of nonlegendary creatures you control with haste
• Infinite creature tokens with haste
• Infinite death triggers
• Infinite ETB
• Infinite lifegain
• Infinite lifegain triggers
• Infinite LTB
• Infinite sacrifice triggers