Yavimaya, Cradle of Growth + Life and Limb + Elesh Norn, Grand Cenobite

Prerequisites

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Steps

1. 1Yavimaya causes all lands to be Forests in addition to their other types, thus Life and Limb causes all lands to be 1/1 Saproling creatures.
2. 2Because Elesh Norn gives all creatures your opponents control -2/-2, they die as a state-based action due to having less than zero toughness.
3. 3Whenever an opponent plays a land, it will also die as a state-based action.

Effects

• Destroy all lands opponents control
• Destroy all lands that enter the battlefield under an opponent's control
• Lock
• Mass Land Denial