Valkyrie

Valkyries are divinities from Norse mythology. The are described as beautiful women wearing armor with white wings, often compared to swans, and are sometimes described as being able to transform into swans. Their duties are to go to battlefields and reap the souls of the valiant warriors, and guide them to Valhalla, where the serve them mead and food. It is unknown why beings with such a positive reputation would serve a Demon Lord. Perhaps they travelled to the Castle to claim the souls of deceased soldiers and vampire hunters and were trapped and corrupted by the castle. This could be likely, since Charlotte explains in Portrai of Ruin that the castle's force bends supernatural creatures to it's will easily.

Aria of Sorrow
While in Dracula's castle, Soma can encounter a Valkyrie. Dracula somehow gets fallen Valkyires to join him and they serve him by defending the Guest House alongside the Persephones. The Valkyries wear Norse Helmet, Norse Armor and Norse boots, with a large loincloth covering their lower body. They prefer to attack by lunging their lance towards Soma. Defeating and dominating a Valkyrie allows Soma to summon her as a Red Bullet Soul. When summoned, a Valkyrie covered in blue aura attacks by swinging her sword upwards, with the cost of 50 MP. She is among the few souls that cast Holy Slash damage to enemies, though she is among the highest class of damagers in the Bullet Soul Class.

Dawn of Sorrow
The Valkyrie returns to Celia's castle to face Soma Cruz. She is depicted as a girl with a pretty face but with a wicked heart. She is still decked out in a set of Norse armor with a white pair of angelic wings and attacks horizontally with a lunge of her lance. Her shield now has a symbol of a dragon on it, possibly a Norse dragon. The Valkyries can be found within the Guest House, although not in the same room as the Persephones, they now attack alongside the Liliths. They are also situated in the Dark Chapel. Defeating them occasionally gives Soma their Breastplate to use and for some strange reason, they also drop pancakes. The Valkyires are fallen angels and it is hard for Soma to "catch" one with his Power of Dominance. But when successfully captured, the Valkyrie Soul allows Soma to summon Valkyrie as a Blue Guardian Soul, which transforms Soma into one of them, as long as the Guardian Soul is activated. When transformed, it cost 30 MP per second to maintain this state. While in this state, Soma/Valkyrie attacks by charging in a straight line, uncontrollably hitting all within range. This time, she abandoned her helmet and allows her blue hair to flow while she charges at an enemy. As her bio stated, she has a pretty face. She also hit her enemies with Holy damage. Valkyrie and Erinys are the only Souls to have Divine Properties. Soma can also allow Yoko to pry Valkyrie out and fuse her with either of two weapons, the Great Sword, or the Halberd. Upgrading the Great Sword allows Yoko to create the Durandal, a giant sword tempered by fairies (Great Sword Class), while upgrading the Halberd will create the Lance, a spear used by the knights (Spear Class).