River Kelpie + Phantom Train + Hardened Academic

River Kelpie

Phantom Train

Hardened Academic

How it works

1. Activate Phantom Train by sacrificing River Kelpie.
2. When River Kelpie dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Hardened Academic and River Kelpie trigger.
4. Resolve the Hardened Academic trigger, putting a +1/+1 counter on River Kelpie.
5. Resolve the River Kelpie trigger, causing you to draw a card.
6. Resolve the Phantom Train ability
7. Repeat.

By feeding River Kelpie to Phantom Train's sacrifice ability, you trigger the Kelpie's persist mechanic to loop it right back onto the battlefield with a -1/-1 counter. This graveyard transition simultaneously awakens Hardened Academic, whose ability uses that departure to place a +1/+1 counter on the Kelpie, neutralizing its -1/-1 counter through state-based actions so the loop can safely repeat. Meanwhile, every time River Kelpie re-enters from the graveyard, its triggered ability lets you draw a card, turning this mechanical cycle into an infinite engine for card advantage and counters.