Jegantha, the Wellspring + Horde of Notions + Mass Hysteria + Phantom Train

Jegantha, the Wellspring

Horde of Notions

Mass Hysteria

Phantom Train

How it works

1. Activate Jegantha by tapping it, adding that cannot be spent to pay generic mana costs.
2. Activate Phantom Train by sacrificing Jegantha.
3. Activate Horde of Notions by paying , causing you to cast Jegantha from your graveyard without paying its mana cost.
4. Repeat.

This looping engine turns a five-color mana source into an unstoppable cycle of resurrection and growth. By tapping Jegantha, the Wellspring, you generate the exact WUBRG required to fund Horde of Notions' ability, bypassing traditional costs entirely. You then feed Jegantha to Phantom Train as an artifact or creature sacrifice, which animates the Train and bulks it up with a +1/+1 counter. From there, Horde of Notions plucks Jegantha right back out of the graveyard onto the battlefield, and Mass Hysteria ensures the revived Jegantha can tap immediately without waiting around for summoning sickness.