Thermopod + Glen Elendra Archmage + Hardened Academic

Thermopod

Glen Elendra Archmage

Hardened Academic

How it works

1. Activate Thermopod by sacrificing Glen Elendra Archmage.
2. When Glen Elendra Archmage 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 Glen Elendra Archmage.
4. Repeat.

This clever loop transforms Glen Elendra Archmage into an endlessly reusable counterspell engine by turning its natural limitation into an advantage. When you sacrifice the Archmage to Thermopod for red mana, its persist ability brings it back with a -1/-1 counter, but Hardened Academic's clever triggered ability swoops in the moment it leaves the graveyard to place a +1/+1 counter on it instead. Because Magic's state-based actions cause +1/+1 and -1/-1 counters to annihilate each other, the Archmage is left completely clean of counters and ready to repeat the process indefinitely.