Seraphina

Seraphina (Serafina) was the older sister of Unity who was close friend of him and Aquarius Dégel when they were young. Some years later, she traveled the world looking for assistance for her country, but she became ill and died. Devastated by his sister's death, Unity decided to use her body as a vessel for Poseidon's soul so he could be free through her and make Bluegrad a prosperous place. Her body was successfully possessed by Poseidon and manifested his powers despite not seeming to have a conscience. In order to stop Poseidon, Dégel locked himself alongside Seraphina and the city of Atlantis inside his ice. She is believed to love Poseidon, so highlighting her status as his host.

Name
Seraphim are, according to Christian theology, the first of the nine "blessed spirits" types of Christian angelology. They belong to the highest order of the highest hierarchy, together with cherubs and thrones, for they are not made in the image and likeness of God, but are part or essence of Him, as "children" of Him.

Characteristics
She is a very sweet and cheerful young woman, smiling and determined, eager to help her people and bring peace to her lands. She certainly also has a maternal side to her younger brother. Her greatest wish is to bring spring to the Blue Graad.

Seraphina has long blue-white hair and very light blue eyes. His eyelashes and eyebrows are also white. Degel says that she looks like her late mother. Her smile warms the hearts of the people around her.

Biography
Seraphina was the older sister of Sea Dragon Unity, daughter of Garcia and also childhood friend of Aquarius Degel. Seraphina was born and spent her entire life in Blue Graad alongside her father and brother. A few years later, she became ill and died. Disturbed by the death of his sister, Unity decided to seal her in the Submarine Sanctuary, next to the oricalco, with the intention of, one day, awakening Poseidon and his sister to serve as his receptacle in order to make Bluegraad a prosperous place.

However, Pandora and Radamanthys try to prevent Aquarius Degel and Scorpio Kardia from successfully completing their mission: negotiating with Poseidon to reach the Lost Canvas. Pandora, commander of the Evil Stars of Hades, breaks the oricalco, responsible for concentrating the power of the Emperor of the Seas. When destroyed, the power disperses and lodges in Serafina, until then kept by the stone. The Sacred Scale of Poseidon dresses her body and the young woman acts, unconsciously, with the powers of the sea deity.

In order to avoid the destruction of the Submarine Sanctuary and generate other even more serious consequences, Degel concentrates all his cosmos and power, sealing Serafina and himself in the Submarine Sanctuary in order to contain the gigantic power of Poseidon in the city of Atlantis.

The Lost Canvas Chronicles
As an ambassador of Blue Graad, Seraphina is invited to the Château de la Vouivre for the ball organized for the birthday of Madame Garnet and she comes accompanied by Dégel who was called there in a mission. While attending the party she and Dégel witness the assault of Fluorite, a maid in Garnet's service, by Lord Jet, one of the guests. Seraphina can be seen telling Degel to intervene, which the Knight gladly does.

A little later, Madame Garnet made her entrance singing, surprising her guests. Noticing Degel's lack of reaction, Garnet asks him to dance with her, much to the disappointment of her suitors and Seraphina.

After the scandal of Madame Flaille who had landed with her mercenaries to obtain revenge for her ruin, and the death of her husband, Garnet invites Dégel to spend the night here. Dégel accepts and accompanies Seraphina back to her coach. Fearing for him, she gives him doubts about him being there, but Dégel reassures her and assures her of her gratitude for having brought him here? following his insistent request to be able to come with her, because he is certain to find his master here. Taking it upon herself, Seraphina says goodbye to Dégel and takes a devastated Mrs. Flaille with her. She prays that nothing happens to her.

While she is on her way, the Jewels attack and kidnap them. Seraphina later wakes up and to her amazement finds herself in Garnet's room. She realizes that she is a prisoner, chained to the foot of the sofa on which she is resting. Hearing a noise, she witnesses Garnet's "meal": she sees her emptying her Carnelian vital energy, one of her Jewels. Shocked, she screams, but Garnet asks her to shut up and explains to her that he is not dead and will soon be as before. Seraphina understands that Garnet is responsible for the recent disappearances in the region. Garnet tells her that certain sacrifices are necessary to establish peace and that she uses her voice for that, then she approaches her in order to steal her life energy.

Later, she is freed by Degel, who ultimately defeats her master and Garnet and sees him cry as she regains her senses. Garnet had only taken enough force from him to stun him.

The lost Canvas
During the fight against Unity, Degel learns from the latter that Seraphina died a few years before. She had caught a cold which got worse because of the climate in her country and eventually died. Shortly afterwards, mad with grief, his brother decided to make her the receptacle of Poseidon in order to revive her and placed her in the Orichalcum while waiting to be able to free Poseidon.

Following the destruction of the protective shell of the Orichalcum, divine power seizes the body of the deceased princess and uses her to unleash its omnipotence against those who dared to awaken it. Degel protects Unity from an attack before returning him with the Orichalcum to Athena. Aquarius sacrifices himself to re-seal Poseidon's power and free Seraphina from his grip. As she dies, Seraphina's soul animates her body for a moment and her face expresses its sadness and regret. Degel joins her by sacrificing himself to freeze the city of Atlantis.

Trivia

 * In a note at the end of Manigoldo's Chronicles, Shiori Teshirogi revealed that Seraphina knew how to wield the Blue Impulse, a technique of Prince Alexei of Blue Graad from the Cygnus Story and Syd of Mizar. She also says that she planned to have Seraphina fight against Carnelian, but that she couldn't fit it into the story.
 * The note also reveals that Fluorite and Seraphina were once the same character, but Shiori decided to create Fluorite to be the female lead of the Gaiden since the reader could identify better with the maid. Curiosly both girls seem to have romantic feelings for Degél, though this is more explicit with Fluorite.
 * The note also says that it was Seraphina who sewed her pwn ball gown and that during the evening she suffered the mockery of the other guests.
 * Based on the etymology of her first name, we can see in Seraphina the exact opposite of Scorpio Kardia: sweet, pure and very concerned about the fate of her comrades, while Kardia is a cynical man and a bit sadistic, didn't give a damn about the reasons for his fights as long as he finds the opponent who will ignite his heart. Both are ill and this disease plays a role in their death: Seraphina died "against her will" from a lung disease, where Cardia despite her illness decided to choose when and how she would die.