Glen Elendra Archmage + Phantom Train + Hardened Academic

Glen Elendra Archmage

Phantom Train

Hardened Academic

How it works

1. Activate Phantom Train 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. Resolve the Phantom Train ability.
5. Repeat.

This fascinating loop centers around Glen Elendra Archmage, which feeds its own counter-canceling engine by jumping back from the graveyard via persist. Each time the Archmage dies to Phantom Train's sacrifice ability, Hardened Academic steps in to place a +1/+1 counter on it as cards leave the graveyard, neatly annihilating the -1/-1 counter from persist. Meanwhile, Phantom Train grows larger with every iteration while continuously fueling an endless stream of artifact creature entries, leaves, deaths, and sacrifices.