Mortuary + Experimental Frenzy + Chamber Sentry

Mortuary

Experimental Frenzy

Chamber Sentry

How it works

1. Cast Chamber Sentry 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 turns the top of your library into an endless revolving door for Chamber Sentry. Because Experimental Frenzy lets you cast spells straight from the top of your library and costs nothing when casting Chamber Sentry for zero mana, the construct immediately enters the battlefield with zero toughness and perishes. This demise triggers Mortuary, which whisks Chamber Sentry right back to the top of your library so you can cast it all over again.