Albertina

One of the princesses of the Claw Clan and the older twin sister of Christina. In contrast to her sister, she is innocent and slow-minded.

She is an Einherjar who's rune allows her to move at superhuman speeds and conceal her presence a little, making her an excellent assassin. She became Yuuto sworn daughter merely because her sister did so as well.

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