Kalastria Highborn + Mortuary + Phyrexian Altar + Bolas's Citadel

Kalastria Highborn

Mortuary

Phyrexian Altar

Bolas's Citadel

How it works

1. Activate Phyrexian Altar by sacrificing Kalastria Highborn, adding .
2. When Kalastria Highborn dies, it and Mortuary trigger.
3. Resolve the Kalastria Highborn trigger, causing you to pay to have an opponent lose 2 life and you to gain 2 life.
4. Resolve the Mortuary trigger, putting Kalastria Highborn from your graveyard onto the top of your library.
5. Cast Kalastria Highborn from the top of your library by paying 2 life.
6. Repeat.

This cunning loop uses Phyrexian Altar to churn your own creatures into mana while setting up a continuous drain. The real engine is Mortuary, which ensures that whenever Kalastria Highborn hits the graveyard, it seamlessly slides right back onto the top of your library. From there, Bolas's Citadel steps in as the ultimate enabler, allowing you to bypass mana costs entirely and recast Kalastria Highborn straight off the top for a mere pittance of life, fueling an endless cycle of blood drain and life recovery.