Anti-Venom, Horrifying Healer + Agatha's Soul Cauldron + Deathbringer Thoctar + The Rollercrusher Ride

Anti-Venom, Horrifying Healer

Agatha's Soul Cauldron

Deathbringer Thoctar

The Rollercrusher Ride

How it works

1. Activate Anti-Venom using Deathbringer Thoctar's ability by removing a +1/+1 counter from it, targeting itself and putting two +1/+1 counters on it due to its replacement effect and The Rollercrusher Ride.
2. Activate Anti-Venom using Deathbringer Thoctar's ability by removing a +1/+1 counter from it, dealing 1 damage to any target.
3. Repeat.

This engine centers around Agatha's Soul Cauldron granting the activated ability of Deathbringer Thoctar to Anti-Venom, Horrifying Healer, turning any +1/+1 counters already on Anti-Venom into direct damage to any target. Normally, removing that counter would cost you your fuel, but Anti-Venom's replacement effect steps in to prevent the damage it would deal to itself, instead converting it into even more +1/+1 counters than you started with. This positive feedback loop is supercharged by The Rollercrusher Ride, whose delirium ability doubles that noncombat damage when your graveyard is stocked, allowing you to easily generate an infinitely growing stockpile of counters and infinite damage to close out the game.