Sephia was the youngest daughter of Zidan, the elvish ruler of Orphea. She never expected to rule her father's kingdom, for she had an elder sister groomed for such a duty. But with said sister disappearing under mysterious circumstances, and her father dying of grief soon after, Sephia had no choice but to assume the rulership of Orphea. While she had her uncle Zirrick by her side as Chancellor, she still doubted her abilities as a monarch.
Her ascent to the throne faced an existential threat with the Lord of the Night's revival and subsequent invasion of her realm. In desperate need of capable warriors, Sephia chose to release the ogre criminal Maggni from the Orphea castle dungeon in exchange for his combat prowess and cooperation. And with the help of him and a small group of elite warriors like Galen, Zazi, and Levv, the elvish forces were able to recapture some of their former strongholds.
Defeating the Lord of the Night and his forces required Sephia to keep the Orb of Light, an artifact of incredible power, away from him. With the help of her friend Zazi, the princess fought past his army in the Holy Mountain to reach the Cavern of Queens, the final resting place of Orphean royalty. There she underwent various trials of strength and wisdom, which culminated in a battle against the sacred Beast of Ophea. Sephia triumphed in that final test, and the Beast made her a Priestess of Light who could also wield the Orb of Light against the encroaching forces of darkness.
Sephia also contributed towards the revival of Galen, arguably the most invaluable warrior fighting on her behalf. When he was at death's door, she transported herself into the same limbo space through prayer. There she helped protect the spirit of a young girl named Rinn, who Galen rescued during the campaign, from the dangerous enemies sent by the Lord of the Night. Sephia's efforts allowed Rinn to reach Galen's wavering soul and lead him back to the land of the living.
The princess also had to contend with an act of betrayal by her Chancellor. Despite knowing the dangers of using the Orb of Light without being a Priestess of Light, Zirrick decided to seize the Orb of Light from Sephia in a bid to single-handedly defeat the Lord of the Night and his army. Doing so turned him into a monster that Sephia had to fight inside the castle walls. After the bout, the princess chose to spare her uncle from further punishment despite his attempted treachery. Instead, she relied more on Zazi, Levv, and (mostly) a resuscitated Galen to defeat the Lord of the Night.
In that final battle, Sephia also learned of the painful truths behind the forces she fought against. She discovered that the Dawn Witch, an invaluable subordinate to the Lord of the Night, was her older sister Kecilia. Furthermore, she learned that Kecilia was responsible for reviving the Lord of the Night in the form of her late betrothed, Rolland, as a means to reunite with him. Sephia almost had to take her own life to keep the Orb of Light away from her deadly foes. But Galen arrived in the throne room to defeat both the Dawn Witch and the Lord of the Night before she needed to take such a drastic measure.
Sephia's story ends with her atop the battlements of Orphea Castle, watching the land restore itself slowly after the Lord of the Night's onslaught. Her last thoughts in the story were with Galen, his whereabouts, and how long she would have to wait before seeing him again.