Mortuary + Garruk's Horde + Chamber Sentry

Mortuary

Garruk's Horde

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 loop turns the zero-mana casting cost of Chamber Sentry into an endless engine of creature entries and deaths. Because Chamber Sentry enters the battlefield with zero toughness when cast for free, it immediately hits the graveyard, allowing Mortuary to effortlessly tuck it right back onto the top of your library. Meanwhile, Garruk's Horde keeps the top of your library revealed and lets you continuously cast that very same Chamber Sentry from the top over and over again, fueling infinite storms and graveyard triggers.