Colfenor, the Last Yew + Gutter Grime + Ashnod's Altar

Colfenor, the Last Yew

Gutter Grime

Ashnod's Altar

How it works

1. Cast the creature card in your hand by paying 0.
2. Either that creature dies as a state-based action due to having zero toughness, or activate Ashnod's Altar by sacrificing that creature, adding CC
3. Gutter Grime triggers, putting a slime counter on it and creating a X/X Ooze creature token.
4. Activate Ashnod's Altar by sacrificing the Ooze, adding CC.
5. When the Ooze dies, Colfenor triggers, returning the creature card from your graveyard to your hand.
6. Repeat.

This loop turns the cycle of life and death into an engine of pure profit by using Colfenor, the Last Yew as a grim recycling center for your graveyard. As you repeatedly sacrifice your creatures to Ashnod's Altar for colorless mana, Gutter Grime eagerly steps in to catch the fallout, growing larger with every fallen comrade and churning out ever-expanding Ooze tokens. When those Oozes inevitably meet the same sacrificial fate at the Altar, Colfenor’s trigger catches the dying tokens—whose toughness is dwarfed by your returning creature cards—to handily bounce your threats right back to your hand for another zero-mana trip to the battlefield.