Mortuary + Mystic Forge + Chamber Sentry

Mortuary

Mystic Forge

Chamber Sentry

How it works

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

This clever loop lets you cast Chamber Sentry for zero mana, allowing it to immediately enter the graveyard with zero toughness and trigger Mortuary to place it right back on top of your library. Mystic Forge makes this process repeatable by letting you look at the top of your library and cast that artifact creature directly from the top, all without spending a single drop of mana. Because Chamber Sentry keeps returning to your hand or library to be cast over and over, you can cycle it indefinitely to build an astronomical storm count or generate an endless stream of creature enters-and-leaves-the-battlefield triggers.