Back in the days of ORIGIN Spectrolichts, there was a friend group: Elaina, Penelope, Ellipse, Dante, and Amos.
Elaina had a little sister named Avera. As opposed to the successful, charismatic and proud Elaina, Avera was seen as a mutt and had always been compared to he sister. The jealousy and self-loathing was slowly consuming her from the inside and eventually, she became corrupted and ran away as a result. After days of searching, Elaina and her friends still could not find Avera - so in a moment of despair and grief, Elaina shattered her lantern and separated her flame into millions of pieces in hopes that one of the creatures who will be born from those flames will eventually find Avera. Hence the very similar form that Spectrolicht take.
The Impact ("Meteor Shower") of the separation had been so powerful that it ravaged everything. Amos was the sole survivor of his group.
The flowers that bloomed after the Meteor Shower seem to take after Amos' friends. Their origin is unknown, but is widely theorised to be connected to the remains of Amos' friends in some way.