Mikaeus, the Unhallowed + Umbral Collar Zealot + Obstinate Gargoyle

Mikaeus, the Unhallowed

Umbral Collar Zealot

Obstinate Gargoyle

How it works

1. Activate Umbral Collar Zealot by sacrificing Obstinate Gargoyle.
2. When Obstinate Gargoyle dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Resolve the Umbral Collar Zealot ability.
4. Activate Umbral Collar Zealot by sacrificing Obstinate Gargoyle.
5. When Obstinate Gargoyle dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
6. Resolve the Umbral Collar Zealot ability.
7. Repeat.

This clever loop works by exploiting the simultaneous interaction of two opposing counter mechanics, turning Mikaeus, the Unhallowed into the ultimate enabler for recursive sacrifice. Because Mikaeus grants undying to non-Human creatures like Obstinate Gargoyle, and the Gargoyle naturally possesses persist, these two abilities alternate each time the creature dies; the +1/+1 counter from undying and the -1/-1 counter from persist continually cancel each other out upon subsequent resurrections. Meanwhile, Umbral Collar Zealot acts as the perfect engine for the loop, giving you a repeatable sacrifice outlet that rewards your sacrifices with infinite surveil triggers.