Therese Alexanderite/Chronology

Volume 5
Some time before the Cal Mira activation event, Glass, L'Arc and Therese had travelled to Raphtalia's World in order to kill the Legendary Heroes to save their own world. Since their levels had been reset after crossing over, L'Arc and Therese had decided to participate in the Cal Mira event to level-up. They end up sharing a room with Naofumi and his party on the boat to Cal Mira and the two parties get along.

After landing in Cal Mira, Therese commissions Naofumi to create a jewelled accessory for her. The two groups agree to go hunting together which turns out to be very successful. Despite Naofumi being the Shield Hero, L'Arc and Therese don't believe it since they had believed the Shield Hero to be the demon described by The Church of the Three Heroes. Later on, Naofumi presents the bracelet he had finished for Therese. Therese is overwhelmed by the beauty and craftsmanship of the piece. The group continue to level-up together until they reach about level 80.

When Naofumi finds the dragon hourglass in Cal Mira, L'Arc and Therese join the forces to fight against the waves. They prove to be incredibly powerful. However, once the boss was defeated, they hesitantly turn on Naofumi since they now believe him to be the Shield Hero. Glass joins L'Arc and Therese and fight against Naofumi's party. However, when Glass became intoxicated, the group retreated back to their world through the waves.

Volume 6
Immediately after returning to their world by the rifts, L'Arc, Glass and Therese go back through to Raphtalia's world, but at a different location. They started upgrading their equipment and accessories to those which were functional in Raphtalia's World. They then used an illusion spell to hide their identities and then went to confront Kyo at the Spirit Tortoise. On the way they passed by Lerno Village where Naofumi was staying..

Volume 7
After the united forces had defeated the Spirit Tortoise, Naofumi and his group had nearly been overwhelmed by Kyo and his forces. However, Glass, L'Arc and Therese had arrived just in time as reinforcements. While their goal was to defeat the Legendary Heroes, they saw Kyo's act of mass murder too criminal to ignore. With the two worlds' heroes together, they were able to defeat Kyo and force him to retreat back to his world. L'Arc, Glass and Therese then jumped in the dimensional rift after him back to their world.

Volume 8
It turns out that the dimensional rift between worlds had been trapped by Kyo. Naofumi's party had been split up while Therese' party had been sent to an infamous prison in their world. However, they were finally able to reunite with Kizuna and Naofumi's party. Together, they are able to defeat Trash II and return to their home nation. The newly-freed Kizuna had learned of L'Arc, Glass and Therese's actions and chastises them for attempting to kill Naofumi and the other heroes. They then apologize and the heroes from both worlds agree to work together.

Volume 9
Therese slowly had become obsessed with Naofumi and his accessory crafting. In exchange for letting her watch, Therese taught the basics of jewel magic to Naofumi. Therese had also participated in the assault on Kyo's laboratory. However, she and the other heroes of Glass' world were teleported away when Kyo summoned an artificial wave.

Volume 17
Several vanguards of the waves had started their assault on the Heroes of Glass' World. They had stolen L'Arc's Vassal Scythe and Ethnobalt's Vassal Boat and had kidnapped the Holy Hunting Tool wielder Kizuna. By the time Naofumi had arrived with reinforcements, the heroes (including Therese) were barely holding off the man who had stolen the Vassal Scythe. However, thanks to Therese sacrificing the accessory Naofumi had created for her and Naofumi's reinforcements, the heroes were able to win and regain the scythe. Naofumi lends her the Two Spirit Charm accessory Imiya had created which gives her a significant power-up. It is slowly becoming clear that Therese is becoming increasingly obsessed with Naofumi and his craftsmanship which makes L'Arc jealous.

Volume 19
With Therese's new obsessive and passionate personality setting in, Naofumi nicknames her Motoyasu III. During the strategy meeting, she comes up with the idea to use Naofumi's accessories to bait other jewels (who would also become obsessed) to join Naofumi's side in the battle. Agreeing, Naofumi gives her two accessories he had created using materials from the Holy Tool Grotto and the Demon Dragon's treasury. This further increases her magical power to at least that of a Hero. During the assault by the vanguards of the waves, Therese' plan proves to be incredibly successful as enemy jewels turned sides upon seeing Therese and the accessories she possesses.