Golgari Thug + Blasting Station + Bolas's Citadel + Vein Ripper

Golgari Thug

Blasting Station

Bolas's Citadel

Vein Ripper

How it works

1. Activate Blasting Station by tapping it and sacrificing Golgari Thug.
2. When Golgari Thug dies, it and Vein Ripper trigger.
3. Resolve the Golgari Thug trigger, putting it from your graveyard onto the top of your library.
4. Resolve the Vein Ripper trigger, causing you to gain 2 life and target opponent to lose 2 life.
5. Resolve the Blasting Station ability.
6. Cast Golgari Thug from the top of your library by paying 2 life.
7. When Golgari Thug enters, Blasting Station triggers, untapping Blasting Station.
8. Repeat.

This loop turns a modest undead rat into an endless engine of destruction by leveraging Bolas's Citadel to cast Golgari Thug straight from the top of your library for a mere 2 life instead of its mana cost. As the Thug repeatedly enters the battlefield, Blasting Station untaps itself thanks to its own passive creature-entry trigger, allowing you to sacrifice the creature over and over to fire off 1 damage at a time. Meanwhile, the constant sacrifice and death triggers feed directly into Vein Ripper, draining your opponents' life totals while padding your own life buffer to comfortably sustain the Citadel's life-payment costs.