Mikaeus, the Unhallowed + Blue, Loyal Raptor + Altar of Dementia

Mikaeus, the Unhallowed

Blue, Loyal Raptor

Altar of Dementia

How it works

1. Activate Altar of Dementia by sacrificing the other Dinosaur.
2. When the Dinosaur dies, its undying ability triggers, returning it from your graveyard to the battlefield without a +1/+1 counter on it due to the -1/-1 counter it will gain from Blue.
3. Resolve the Altar of Dementia ability.
4. Repeat.

This delightfully clever combo turns your graveyard into an infinite mill engine by exploiting a counter-balancing rules quirk. While Altar of Dementia provides the sacrifice outlet that turns your creature into milled cards, Mikaeus, the Unhallowed is the engine's beating heart, granting undying to your non-Human creatures so they constantly return from the dead. Blue, Loyal Raptor makes the whole loop self-sustaining by distributing a -1/-1 counter whenever the creature enters the battlefield, neatly wiping away the +1/+1 counter from undying and allowing the cycle to repeat indefinitely.