Mortuary + Bolas's Citadel + Hangarback Walker

Mortuary

Bolas's Citadel

Hangarback Walker

How it works

1. Cast Hangarback Walker either from your hand by paying 0 or from the top of your library by paying 0 life.
2. Hangarback Walker enters and dies as a state-based action due to having 0 toughness.
3. Mortuary triggers, putting Hangarback Walker from your graveyard onto the top of your library.
4. Repeat.

This clever loop turns zero-mana investments into an endless mechanical engine by leveraging Bolas's Citadel to cast Hangarback Walker off the top of your library for zero life. As soon as the construct hits the board, it immediately succumbs to state-based actions with zero toughness, triggering Mortuary to seamlessly place Hangarback Walker right back onto the top of your library. Because Bolas's Citadel lets you continuously play from that very same top deck spot, you can cycle the artifact through death and rebirth infinitely.