Phyrexian Altar + Glen Elendra Archmage + Hardened Academic

Phyrexian Altar

Glen Elendra Archmage

Hardened Academic

How it works

1. Activate Phyrexian Altar 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 loop turns the recursion of Glen Elendra Archmage into a self-sustaining engine by pairing it with Phyrexian Altar to constantly sacrifice the Archmage for any color of mana. Because Glen Elendra Archmage enters the graveyard and then returns via persist with a -1/-1 counter, Hardened Academic steps in with its graveyard-trigger to place a +1/+1 counter on the Archmage, which immediately neutralizes the -1/-1 counter through state-based actions. This meticulous counter-cancellation ensures the Archmage never accumulates lingering -1/-1 counters, allowing you to repeat the sacrifice indefinitely and harvest boundless mana along with an endless stream of entry, death, and sacrifice triggers.