Mortuary + Phyrexian Altar + Crimson Kobolds + Bolas's Citadel

Mortuary

Phyrexian Altar

Crimson Kobolds

Bolas's Citadel

How it works

1. Activate Phyrexian Altar by sacrificing Crimson Kobolds
2. When Crimson Kobolds dies, Mortuary triggers, putting Crimson Kobolds from your graveyard onto the top of your library.
3. Cast Crimson Kobolds from the top of your library by paying 0 life.
4. Repeat.

This clever loop relies on the zero mana value of Crimson Kobolds to bypass Bolas's Citadel's life-payment restriction, letting you cast it from the top of your library for free over and over again. Each time you sacrifice the Kobolds to Phyrexian Altar, you generate a mana of any color while triggering Mortuary, which instantly places the creature right back on top of your library to restart the cycle. Because the Citadel lets you play cards directly from that top position without paying mana costs, this seamless exchange creates an endless engine of colored mana, storm count, and death triggers.