A boy who was found collapsed in the forest and rescued by Crevanille and Regina. He and his father had been pursued by bandits, and his father died while Remus barely escaped. They brought Remus to their mercenary camp to recover. Since then he came to live with them as a member of the Alten Schwart brigade. It became Crevanille's duty to look after him because they were the closest in age. Thanks to Crevanille, Remus made a quick recovery. He decided to learn healing so that he could help injured comrades since he couldn't fight in combat yet. He thought of the mercenary group as close family.
At their new mercenary mission in Lamplast Island, Remus requested Dixon to let him participate in battle. After this first battle, Remus was troubled over the thought of having killed another human being. Dixon spoke to him and calmed him down.
The angel Akyel attacked Lamplast Island with devastating power and killed many people. Dixon needed to commence on a new mission away from the Alten Schwart mercenaries in order to investigate the angels. Dixon separated from the mercenaries, leaving it to Bauer and let all the members decide what they wanted to do individually. Remus went with Dixon and Crevanille because he had no other place to go. Their new mission was to investigate ruins for clues to find a way to defeat the angels.
They traveled to the Ruins of Hope which was in Dulkheim. They set up camp and Remus went to gather firewood. Meanwhile, Vester appeared and killed Dixon and Regina. Vester critically wounded Crevanille. Crevanille recovered and Remus gave him the unfortunate news. The two of them carried on Dixon's plan of exploring the ruins. They entered the Ruins of Hope and came to the deepest room, where Crevanille suddenly spurt wings of blood from his back and fell unconscious. They were discovered by Dulkheim soldiers and taken to a military base called Leinfaltz.
Ludwig convinced Crevanille to join the Dulkheim military because he was a Ruin Child, one who could open the doors in ancient ruins. By joining, Crevanille and Remus had permission to legally enter ruins in Dulkheim, and they wanted to make the most of this as it was their own objective to investigate ruins. During their stay at Fort Leinfaltz, they learned magic. Remus became able to see angels.
They went to Ribocca village to visit Dixon's wife and tell her the unfortunate news that Dixon and Regina were killed. Remus had previously been exchanging letters with her. The village came under attack by a replica angel and all the villagers were killed, including Dixon's wife. Remus came to hate angels with a passion for killing many innocent humans. He was determined to find a way to destroy them.
He grew close to Crevanille but one day they were assigned to be separated. The Ruin Children at Fort Leinfaltz were secretly imprisoned for experimentation. Remus found out from Lumis and rescued them from prison. He, Crevanille, Frayne, and other surviving Ruin Children escaped by boat out of Dulkheim. They became shipwrecked and ended up in Marquelay, rescued by Eliza.
They were invited to stay there and used it as a home base. Siding with Marquelay and aligning with Princess Alicia, the had to deal with the angel threat and fight in the war. While in Marquelia, Crevanille and Eliza saw a girl that looked very similar to Remus. Remus tried relentlessly to find her because he was told by his father that he had a twin sister.
Before he met Crevanille, Remus had been traveling with his father. He did not even know his father's lineage or the reason for traveling. This mystery would be revealed in Marquelay. There was a written prophecy that stated that if twins were born in the Marquelay royal family, the downfall of the kingdom would come. At the time they are born, a great calamity would sweep across the whole continent. Attempting to prevent this from fulfilling, Renish the former king of Marquelay took his son Remus and left the country.
Princess Alicia is Remus' twin sister, but she needed to keep it a secret. He encountered her but she didn't tell him her true identity at first. After time she finally revealed the truth to Remus. Although he was finally reunited with his sister, he chose not to stay in Marquelay castle but to keep traveling with Crevanille. The prophecy was fulfilled and Alicia ended the Marquelay monarchy, choosing to form a democratic nation.