Story Summary

Finn is the descendant of 4 different demigods. Her mother is Peritia Imaginnos, Patron of Imagination, whose parents are Kao Aedifex, Patron of Chaos and Embla, God of Totems. Her father is Renova Ignae, Patron of Fire. He will be playing a main part in the story, so take note.
Two of the Three Goddesses want Finn to destroy the universe, since Lady Time is running out of power. The Third Goddess, Lady Luck, doesn't want the universe to end and so hides Finn away as an orphan, in the hopes she doesn't want to destroy the universe. Finn goes from home to home because of her destructive tendencies, eventually finding a home that accepts her. One of these people is Evelyn, whom Finn emotionally attatches herself to.
We begin the story as they're heading out to the equivalent of college. Evelyn had always wanted to be a priestess, called a Chromai, able to communicate with the Goddesses. Finn wasn't sure where she wanted to go, since she doesn't want to be a Chromai, but she's dependent on Evelyn. She eventually decides on being a Renovite (soldier) since she's always looked up to Renova.
At the Renovite Barracks, she sees Renova conversing with the upper-rank soldiers. This scene can be used to enforce her admiration of Renova, as a set up for later.

Finn gets angry at another of the students, and uses her destructive powers. Perhaps she's in danger instead????

Renova takes notice, and decides he'll manipulate her into becoming a weapon for an overseas warmonger. He takes her to a private location where he hopes to train her. (don't look him in the eyes scene)
Renova can't truly manipulate Finn until Evelyn is dead because Finn is so attached to her. Evelyn receives a message from the Goddesses to go there.
Finn goes bananas now that the person she depended on is now gone. Magic manacles are placed on her that drain her destructive powers and store it for use in weapons overseas. Renova proceeds to wear her down until she has no fight left in her. (The manacles won't come off until you give up yourself to me)
Meanwhile, Evelyn is resurrected as a cat and sent on a mission: Find a team and get the demigods' artefacts to save the universe. It takes a year for her to be resurrected, and then another year to collect all the artefacts. This can be another novel or even series, especially exploring the world as a whole.
Finn is sent to Silenda Sicarius to get trained up? Or perhaps Renova trains her? Silenda teaches her to loosen up, as she's too stiff and robotic, as well as Dark (Shadow) Magic. Silenda also teaches Finn how to take control of her life, as she is just like other assassins she's seen before.
Eventually, Evelyn confronts Finn and Renova. They found out Finn is also a demigod, and so they need her artefact for it to work. Unfortunately, she doesn't know what hers is. Evelyn almost convinces Finn to leave Renova. However, Renova kills Evelyn again. The manacles are put on Finn again, but this time she has skills on her side. She defeats Renova, and in her grief destroys the universe... and her emotions.
The team that Evelyn collected are safe because of one of the artefacts. They are still trying to revive the universe.

Perhaps Finn confronts the Goddesses, and while she's gone, the other demigods revive the universe. It was the Goddesses plan the entire time, and they were all just chess pieces. Perhaps the Theme is about free will when gods are involved.

Perhaps the universe stays gone, and it is a message about consequences and finality?

Perhaps the universe is brought back, but Finn becomes a slave to Renova.

Destruction is part of creation. It allows for a blank canvas on which something can be created. It is equal in all things and nondiscriminatory.