Jegantha, the Wellspring + Horde of Notions + Yahenni, Undying Partisan + Fires of Yavimaya

Jegantha, the Wellspring

Horde of Notions

Yahenni, Undying Partisan

Fires of Yavimaya

How it works

1. Activate Jegantha by tapping it, adding that cannot be spent to pay generic mana costs.
2. Activate Yahenni 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 loop turns Jegantha, the Wellspring into a self-sustaining engine by tapping it for the exact five-color mana requirement needed to activate Horde of Notions, which then plucks Jegantha right back out of the graveyard for free. To bridge the gap, Yahenni, Undying Partisan steps in as the sacrifice outlet to send Jegantha back to the graveyard while growing larger with each iteration. Meanwhile, Fires of Yavimaya provides the crucial haste that allows Jegantha to tap for mana the very moment it re-enters the battlefield, letting you cycle this sequence infinitely for endless triggers.