Mortuary + Blasting Station + Bolas's Citadel + Serrated Scorpion

Mortuary

Blasting Station

Bolas's Citadel

Serrated Scorpion

How it works

1. Activate Blasting Station by tapping it and sacrificing Serrated Scorpion.
2. When Serrated Scorpion dies, it and Mortuary triggers.
3. Resolve the Mortuary trigger, putting Serrated Scorpion from your graveyard onto the top of your library.
4. Resolve the Serrated Scorpion trigger, causing you to gain 2 life and dealing 2 damage to each opponent.
5. Resolve the Blasting Station ability.
6. Cast Serrated Scorpion from the top of your library by paying 1 life due to Bolas's Citadel.
7. When Serrated Scorpion enters, Blasting Station triggers, untapping Blasting Station.
8. Repeat.

This clever loop transforms Bolas's Citadel from a card-advantage engine into a self-sustaining finisher by leveraging the top of your library as a recurring resource. Whenever Blasting Station sacrifices Serrated Scorpion, Mortuary immediately tucks that insect back onto your library just in time for Bolas's Citadel to let you recast it for a mere 1 life—effortlessly offsetting the life cost with the scorpion's own life-draining death trigger. Meanwhile, Blasting Station's untap ability ensures the sacrifice outlet resets itself with every single entry, creating an endless cycle of damage and life gain that grinds down your opponents.