Originally Odin's bodyguard. After the battle with Loki and Fenrir, Odin leaves her in Issei's town. She then gets persuaded by Rias to become her servant. She remains in Kuou Academy as a teacher. Rossweisse is known to be a very serious person. She has a tendency to buy things at sales when they're cheap, allowing Issei to coin for her the nickname "The 100-Yen Shop Valkyrie". Rossweisse makes her first appearance in Volume 5 as Odin's bodyguard, reminding him of his status and telling him not to look at Serafall Leviathan lecherously. Odin responds by mocking her for not having a boyfriend. Rossweisse is highly proficient in the use of Norse magic, specializing in long-range and bombarding attacks. She is capable of using ice, fire, water, lightning, wind, thunder, light, summoning, and explosive-based magic. Upon returning from her training in Valhalla in Volume 12, she starts to use defensive spells (using the trait of Rook) which are strong enough to easily shield against Balance Breakers.
