Mortuary + Vizier of the Menagerie + Chamber Sentry

Mortuary

Vizier of the Menagerie

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 crafty loop revolves around casting a zero-mana artifact creature over and over again. When you cast Chamber Sentry for zero mana, it immediately hits the graveyard due to having zero toughness, which triggers Mortuary to conveniently place it right back on top of your library. From there, Vizier of the Menagerie lets you peer into the future and instantly recast Chamber Sentry from the top of your library, fueling an endless cycle of enters-the-battlefield and death triggers.