Christina

One of the princesses of the Claw Clan and the younger twin sister of Albertina. In contrast to her sister, she is mischievous and intelligent.

She is an Eingerjar who's rune allows her to conceal her presence and increase her speed a little, which, along with her information gathering skills, makes her an excellent spy. She became Yuuto's sworn daughter due to her respecting his leadership skills.

(Source: The Master of Ragnarok & Blesser of Einherjar Wiki)