Ragnarök is Chrona's Demon Sword partner. Ragnarök is the first inhuman weapon introduced in Soul Eater. It loves to degrade and pester Chrona (even during fights) by giving him noogies, pinching his nose, hitting him on the head, or taking his food. When Chrona finally tells Ragnarök to stop, Ragnarok seems surprised at his reaction. Ragnarök has taken to absorbing any soul, evil or not. By taken innocent souls, Ragnarök soul wavelength has grown out of control and vastly overpowers Chrona's own wavelength, which will lead to Ragnarök soul eating Chrona's soul in the end. Later on, Ragnarök can change its appearance to that of a dragon to give Chrona wings to fly vastly increasing Chrona's combat capablilties. It can also grow a mouth on its sword form that draws souls to it by using a high pitched scream. Then Ragnarök absorbs the souls, using the mouth like a vacuum. Also, while screaming in its sword form, Ragnarök acts like an electric saw due to the vibrations caused by its screaming. Ragnarök can control Chrona's black blood (due to consuming innocent souls) when it leave Chrona's body. It can use the blood spilled from Chrona's body to make spikes to attack anyone or can cause the blood to stop and act like a bandage for Chrona so it does not pass out from blood loss. When not in use, Ragnarök resides in Chrona's body, further tainting his blood and also allowing him to control Chrona's blood, Ragnarök commented that Maka's soul looked delicious. Whether Ragnarök can actually see souls has yet to been seen. He does worry about Chrona's health and will try to help Chrona by stopping his bleeding wounds. However, Ragnarök will always ask for thanks afterwards. After the fight with Maka Ragnarok had all his souls confiscated which resulted in him shrinking greatly in size (he now resembles a chibi form of himself) he is also slightly perverted since when Chrona finally stood up to him he acted like an understanding guy while at the same time pulling up Chrona's dress, also he lifted Maka's skirt and commented on her dull choice of panties. Even with less power he still wants to eat any soul he sees, he also tends to us Chrona as a human shield against non-deadly attacks like the Maka Chop. Attacks: His attacks mostly concentrate using Chrona's blood and causing mass destruction. Blood Spike: Changes the drops of Chrona's blood into spikes to attack from multiple angles. Screech Resonance: Ragnarök's equivalent of Soul Resonance. Jet Black Sword: a more powerful form of Ragnarök's sword form. (Source: SoulEaterFan)
He has a soul so strong that it counts for ninety-nine souls by itself. Black Star was about to take his soul but stopped when he saw how Mifune was protecting the young witch, Angela. He acts like a big brother or even a father to Angela. He is later a bodyguard for Arachne but only because she is holding Angela captive though Angela doesn't know it. He seems to really like being with children since he blushed at the thought after Tsubaki suggested that he could be a teacher at Shibusen. Mifune used to be the bodyguard for a mafia family, when he was sent to kill a rival family and retrieve the witch that they had, he met Angela. After 'kidnapping' her he left the family to protect her. He also compliments Tsubaki, stating that she is a great weapon and has a lot of potential (making her blush). His name comes from legendary Japanese actor Toshiro Mifune. Attacks: His attacks center around his Infinite One-Sword Style. He uses the blunt side of the sword if he has to fight children, first shown in the first fight he had with Black Star. However, he may also use his swords by throwing them into the ground and using them as platforms to travel across. Start Up: Not an attack but more like the signal for Mifune of the start of the fight by throwing his case of swords into the air then letting stick into the ground, surrounding his enemy and himself with swords thus giving Mifune an near unlimited amount of swords to use. Three Shining Paths: Mifune will grab then throw three swords at the enemy. Addition Blows (1-12 Blows): Mifune moves at high speeds to attack his enemy. After each hit he will let go of his sword to quickly use another to let him attack from different angles while his enemy is stunned from his previous blow. This leaves his enemy covered with twelve swords. Multiplication Twenty Four Blows: Mifune will follow his Addition Blows with this attack. He strikes the swords that he left around his enemy from his Addition Blows which ends up cutting his enemy with the twelve swords all over again. (Source: Wikipedia)
Mizune is the surname of a large family of witches who all look alike and whose animal theme are mice. They speak by saying, "chi" (sound of a mouse squeak). One witch from this family is initially introduced as a friend of Eruka's. Like Eruka, she does not like the fact that Medusa has so much freedom and that she brings Chrona to the witch meetings. Mizune and Eruka try to kill her for endangering all witches while she is staying at Shibusen. Mizune is killed by Medusa when Medusa set off her snake bombs that she had implanted in Mizune's body. Five members of the family join Medusa after Eruka tells them that their family member that Medusa killed was actually killed by a Shibusen student. The five family members can merge into a single being capable of actual speech. The form is of a good-looking young woman with short pink hair with a hat, long skirt, and a shirt showing her stomach and a good portion of her breasts; this exposed portion is most likely where the deceased Mizune covered. (ref:Wiki)
Rasputin was only shown in the series for a few minutes, but from the statements that Rasputin made it was implied that his body was invulnerable against any form of bullet.
Bloodthirsty killer of Emerald Lake Sonson J. (ソンソンJ, Sonson Jei) was an evil human soul.
The Death Scythe in charge of East Asia. She comes off as being bookish and analytical, she is very respectful to all, she was the one that talked Marie out of marrying a toilet using wordplay. She was the student council president when Stein and the other Death Scythes were students, she was the person that scolded Spirit for his endless flirting and Stein's urge to dissect everything, she was said to have been a small, yet talkative child. She still treats the others as little kids like a teacher would (clapping to get their attention and telling them to line up and walk in a single file line) much to the embarrassment of the others. In recent chapters it is shown that she takes the form of a crossbow, able to fire high pressure spirit shots up to 10 km accurately. She is also suggested to have a genius IQ, and is an extremely competent information gatherer and tactician, easily finding one of Arachnephobia's labs. - Wiki
Harvar is Ox's weapon and takes the form of a lance. In weapon form, he has the power of lightning. Like Ox, he is named after a university (in this case, Harvard). His last name is derived from the French word for lightning. Like most weapons, he can change a part of his body into his weapon form; in his case, he can turn one his hands into the point of his lance form, as well as generate an electric charge through an unchanged hand. As evident during the infiltration of the Arachnophobia castle, he is fiercely loyal to Ox and prioritizes his safety above all else while maintaining an ice-cold composure in battle even when Ox does not. -wikipedia