Kithkin Spellduster + Phantom Train + Hardened Academic

Kithkin Spellduster

Phantom Train

Hardened Academic

How it works

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

This clever loop transforms Phantom Train into an endless sacrifice engine by feeding it Kithkin Spellduster over and over again. Every time the Spellduster perishes and triggers its persist ability to return to the battlefield with a -1/-1 counter, Hardened Academic steps in as a brilliant passive enabler, spotting the card leaving your graveyard and placing a +1/+1 counter on the Spellduster. Because +1/+1 and -1/-1 counters actively annihilate each other as a state-based action, this counter neutralization completely clears the Spellduster's slate—leaving it entirely free of counters so it can persist all over again the next time it's fed to the Train.