A Spanish female fencer who fights with a Plasma Rapier. She happens to be a long-time friend of Gerelt, in which she works with him under Bilstein. It is unclear of why Claire had joined the Fourth Empire, but it is speculated that something tragic had happened to her in the past and that she saw the Fourth Empire as a way of escaping her own inner pain and suffering.
In battle, Claire is known as Scarlet Del Sol and is a master at fencing, using her precise fencing skills to mercilessly defeat her opponents. Unlike Gerelt, Claire is very loyal to Bilstein and holds the button to the bomb planted inside Gerelt's chest. Upon hearing and learning about Gerelt's revolt against Bilstein, Claire confronts him and demands an explanation from Gerelt, leading to an impromptu battle between the two fencers.
Before Claire can make her final move against Gerelt, Luca confronts them unexpectedly, under orders from Gore to eliminate Claire. When Luca explodes from a Plasma energy overload due to the intensity of the struggle, Claire shields Gerelt from the blast and dies in his arms. It is heavily implied from within Claire's last words that she may have developed feelings for Gerelt during their time together in the Fourth Empire, and that she had wanted to spend the rest of her life with him.