Agatha's Soul Cauldron + Triskelion + Evernight Shade

Agatha's Soul Cauldron

Triskelion

Evernight Shade

How it works

1. Activate Evernight Shade using Triskelion's ability by removing a +1/+1 counter from it.
2. Repeat step 1 until Evernight Shade has no +1/+1 counters on it.
3. Resolve all Evernight Shade abilities dealing 1 damage to Evernight Shade, and any remaining damage to any target(s).
4. Evernight Shade dies as a state-based action due to having 0 toughness.
5. Evernight Shade's undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
6. Repeat.

This ingenious loop relies on Agatha's Soul Cauldron to grant activated abilities across your battlefield, using its mana-fixing capability to fuel the engine. By exiling Triskelion, you gift its counter-removal and damage-dealing ability to Evernight Shade, which already boasts its own pump activation. You can then repeatedly strip away Evernight Shade's +1/+1 counters to deal lethal damage to the shade itself while redirecting excess pings anywhere you choose. Once the shade perishes from zero toughness, its native undying ability revives it with a fresh counter, ready to repeat the entire cycle indefinitely.