Colfenor, the Last Yew + Pawn of Ulamog + Walking Ballista

Colfenor, the Last Yew

Pawn of Ulamog

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. Colfenor and Pawn of Ulamog trigger.
4. Resolve the Colfenor trigger, returning nothing from your graveyard to your hand.
5. Resolve the Pawn of Ulamog trigger, creating a 0/1 Eldrazi Spawn creature token.
6. Activate the Eldrazi Spawn by sacrificing it, adding C.
7. The Eldrazi Spawn dies, triggering Colfenor, returning Walking Ballista from your graveyard to your hand.
8. Repeat.
9. Once you have a large amount of C, you may cast Walking Ballista using an arbitrarily large amount of mana, then use its ability to deal infinite damage to any target(s).