Zenith Festival

“Harmonize [cost]” means “You may cast this card from your graveyard by paying [cost] and tapping up to one untapped creature you control rather than paying the spell’s mana cost,” “If you cast this spell using its harmonize ability, its total cost is reduced by an amount of generic mana equal to the tapped creature’s power,” and “If the harmonize cost was paid, exile this card instead of putting it anywhere else any time it would leave the stack.”

Tapping a creature won’t reduce colored mana components of harmonize costs.

You must still follow any timing restrictions and permissions, including those based on the card’s type. For instance, you can cast a sorcery using harmonize only when you could normally cast a sorcery.

A spell cast using harmonize will always be exiled afterward, whether it resolves, is countered, or leaves the stack in some other way.