Emil Castagnier

Emil Castagnier is the son of Reysol and Lana Castagnier and the nephew of Flora and Alba.

Personality
He is portrayed as a coward, but promises to protect Marta Lualdi, the bearer of the Ratatosk Core by forming a contract with the Lord of Monsters, Ratatosk, thus making him the Knight of Ratatosk. In the duration of this phase, Emil is more violent and blood-thirsty, which is why some call him a monster. This form is later on called "Ratatosk Mode".

In Tales of Symphonia
Emil's parents were killed by Decus posing as Lloyd Irving. Emil is shown to have saved Marta during the Palmacosta Blood Purge. However, he leaves her with barely a word, returning to his parents, who are dying from wounds that Decus had inflicted on them. His mother's final words were to find his relatives in Luin. After this introductory sequence, the story skips forward in time. Emil is in Luin, living with his Aunt Flora and Uncle Alba, yet he is shown to be timid, indecisive, and otherwise cowardly. He has a less than loving relationship with the two, in addition to the rest of the town, due to him being a so-called, "supporter" of the Vanguard, an organization that wishes to free the Sylvaranti people from oppression, and against Lloyd, who led the attack in the Blood Purge, but is, ironically, a true hero to almost every person in the game for leading the Chosen, Colette in the Journey of Regeneration. He is also highly revered in Luin after rebuilding their town.

With the "spirit" of Emil and physical form of Aster, he was able hide after being attacked by Richter Abend. The Emil who acts as the protagonist in the story is the personality Ratatosk created which grows from his experiences after fleeing Palmacosta. Some clues that other characters are aware the new Emil does not look like the real Emil despite taking on his identity he meets Ms. Dorr, the widow of Palmacosta's governor-general, and Thomas, Emil's apparent next-door neighbor, both stated that they didn't recognize Emil, but eventually let it slide. Tenebrae chose to let Emil/Ratatosk live for a while without telling him the truth, even letting him believe the core on Marta's forehead is real so the gathering of the other Centurion's cores would be easier. The pact with Ratatosk and the title of Knight of Ratatosk that go with it in fact do not exist, and are fabrications by Tenebrae.