Jegantha, the Wellspring + Horde of Notions + Anger + Phantom Train

Jegantha, the Wellspring

Horde of Notions

Anger

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 clever loop uses Horde of Notions as an engine, relying on its ability to pull Jegantha, the Wellspring right back out of your graveyard for its exact five-color activation cost. Jegantha pays for this resurrection directly by tapping for {W}{U}{B}{R}{G}, sidestepping its own restriction since Horde's cost has no generic mana to pay. Meanwhile, Phantom Train serves as the sacrifice outlet to send Jegantha back to the graveyard while growing itself with +1/+1 counters, and Anger hangs out in the graveyard to ensure everything keeps moving fast with continuous haste as long as you control a Mountain.