Ashaya, Soul of the Wild, Blossoming Tortoise, Karn, Silver Golem, and Mycosynth Lattice

Prerequisites

• Ashaya, Soul of the Wild on the battlefield
• Blossoming Tortoise on the battlefield
• Karn, Silver Golem on the battlefield
• Mycosynth Lattice on the battlefield

Steps

1. Acitvate Karn by paying due to Blossoming Tortoise, causing a land an opponent controls to become a 0/0 artifact creature
2. The land dies as a state-based action due to having 0 toughness
3. Repeat
4. You may also repeat this loop whenever a land enters the battlefield under an opponent's control, and you may repeat this for any permanents opponents control with mana value equal to zero

Results

• Destroy all lands opponents control
• Destroy all lands that enter the battlefield under an opponent's control