Mikaeus, the Unhallowed + Blasting Station + Trapjaw Kelpie

Mikaeus, the Unhallowed

Blasting Station

Trapjaw Kelpie

How it works

1. Activate Blasting Station by tapping it and sacrificing Trapjaw Kelpie.
2. When Trapjaw Kelpie dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When Trapjaw Kelpie enters, Blasting Station triggers, untapping Blasting Station.
4. Resolve the Blasting Station ability from step 1.
5. Activate Blasting Station by tapping it and sacrificing Trapjaw Kelpie.
6. When Trapjaw Kelpie dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
7. When Trapjaw Kelpie enters, Blasting Station triggers, untapping Blasting Station.
8. Resolve the Blasting Station ability from step 5.
9. Repeat.

This clever loop relies on the constant counter-manipulation between Trapjaw Kelpie, Mikaeus, the Unhallowed, and Blasting Station to turn an ordinary frog lizard into an infinite-damage engine. Because Trapjaw Kelpie naturally enters with a -1/-1 counter from persist, sacrificing it to Blasting Station allows Mikaeus, the Unhallowed's undying grant to bring it back with a +1/+1 counter instead; those two opposing counters immediately annihilate each other through state-based actions, leaving the creature completely clean of counters and ready for the cycle to repeat. Every single iteration untaps Blasting Station thanks to its own triggered ability upon the creature's re-entry, letting you machine-gun an opponent's life total down to zero through endless sacrifice.