I kind of wish What Angel Wakes Me (the lyrics to the Titania fight) was used as inspiration and turned into a gauge spell where Lily* and Seraph hold/clasp hands and dance in ring while throwing glowing petals everywhere (circle dance or waltz?) to produce a spell effect. Maybe something like Fey Union + Seraphic Veil**? Or something else?

*(Name of our fairy. Would be Eos or Selene depending on which you have summoned)
** (on Aetherpact/Fey union target)