Altar of Dementia + Kithkin Spellduster + Hardened Academic

Altar of Dementia

Kithkin Spellduster

Hardened Academic

How it works

1. Activate Altar of Dementia by sacrificing Kithkin Spellduster.
2. When Kithkin Spellduster dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Hardened Academic triggers, putting a +1/+1 counter on Kithkin Spellduster.
4. Resolve the Altar of Dementia ability.
5. Repeat.

This crafty loop centers on Kithkin Spellduster and its persist ability, which normally would exhaust its own usefulness after a single return to the battlefield. However, Hardened Academic completely bypasses this limitation by watching cards leave your graveyard and rewarding that event with a +1/+1 counter. Because the persist trigger and Hardened Academic's triggered ability both place counters on Kithkin Spellduster as it returns, state-based actions cause the +1/+1 and -1/+1 counters to annihilate each other, leaving the creature completely clean of counters. With Altar of Dementia serving as the sacrifice outlet to continuously feed the graveyard and mill your opponents along the way, this engine keeps spinning indefinitely.