I accidentally setup my opponent the other day in Arena with Infinite Life...
My opponent had a lotus cobra on the battle with 6 mana, was playing a deck focused on lands and biggies...then I played confounding conundrum...
"Whenever a land enters the battlefield under an opponent's control, if that player had another land enter the battlefield under their control this turn, they return a land they control to its owner's hand."
Next turn they play Ashaya, Soul of the Wild followed by Gilded Goose...which gets returned to hand and can be replayed indefinitely due to it counting as a land and Lotus Cobra producing mana which makes an infinite supply of food and mana
Major backfire lol
Oh, forgot to mention, they also had a Schrute Swarm on the battlefield with Lotus Cobra so Infinite Insects as well, I think I let it get up to a few hundred before I conceded just for kicks.
My opponent had a lotus cobra on the battle with 6 mana, was playing a deck focused on lands and biggies...then I played confounding conundrum...
"Whenever a land enters the battlefield under an opponent's control, if that player had another land enter the battlefield under their control this turn, they return a land they control to its owner's hand."
Next turn they play Ashaya, Soul of the Wild followed by Gilded Goose...which gets returned to hand and can be replayed indefinitely due to it counting as a land and Lotus Cobra producing mana which makes an infinite supply of food and mana
Major backfire lol
Oh, forgot to mention, they also had a Schrute Swarm on the battlefield with Lotus Cobra so Infinite Insects as well, I think I let it get up to a few hundred before I conceded just for kicks.