Yedora, Grave Gardener + Storm Cauldron + Walking Ballista

Yedora, Grave Gardener

Storm Cauldron

Walking Ballista

How it works

1. Cast Walking Ballista by paying 0.
2. Walking Ballista enters the battlefield and dies as a state-based action due to having zero or less toughness.
3. Yedora triggers, returning Walking Ballista from your graveyard to the battlefield face down as a Forest land.
4. Activate Walking Ballista by tapping it, adding .
5. Storm Cauldron triggers, returning Walking Ballista from the battlefield to your hand.
6. Repeat.
7. Once you have infinite green mana, you may use it to cast Walking Ballista for an arbitrarily large amount of mana, and then use its ability to deal infinite damage to any target(s).