Ragnarök is Chrona's Demon Sword partner and the first inhuman weapon introduced in Soul Eater. It delights in mocking and harassing Chrona, even during battles, by giving noogies, pinching his nose, hitting him on the head, or stealing his food. When Chrona finally asks Ragnarök to stop, it seems genuinely surprised by his reaction. Ragnarök has developed a habit of absorbing any soul, regardless of its nature. By consuming innocent souls, Ragnarök's soul wavelength has grown uncontrollably, vastly overpowering Chrona's own wavelength, which will eventually lead to Ragnarök devouring Chrona's soul.
Later on, Ragnarök can transform into a dragon form, granting Chrona wings for flight and significantly enhancing his combat capabilities. Additionally, in sword form, Ragnarök can grow a mouth that emits a high-pitched scream to attract souls, which it then absorbs like a vacuum. While screaming, Ragnarök functions similarly to an electric saw due to the vibrations caused by its cry. It can control Chrona's black blood (due to consuming innocent souls) when it leaves Chrona's body. Using the spilled blood, Ragnarök can create spikes for attacks or use the blood to seal wounds, acting as a bandage to prevent Chrona from fainting due to blood loss.
When not in use, Ragnarök resides within Chrona's body, further tainting his blood and allowing it to control Chrona's blood. Ragnarök once commented that Maka's soul looked delicious, though whether it can actually see souls remains unclear. Despite its often antagonistic behavior, Ragnarök does worry about Chrona's health and will attempt to help by stopping his bleeding wounds, although it always demands thanks afterward. After the fight with Maka, all of Ragnarök's souls were confiscated, causing it to shrink dramatically in size (now resembling a chibi version of itself). It also exhibits slight perversion; for example, when Chrona stood up to it, Ragnarök acted understanding while simultaneously lifting Chrona's dress and later commenting on Maka's dull choice of panties after lifting her skirt.
Even with diminished power, Ragnarök still desires to consume any soul it sees and tends to use Chrona as a human shield against non-lethal attacks like the Maka Chop.
Attacks: Most of Ragnarök's attacks focus on using Chrona's blood to cause extensive damage.
- Blood Spike: Transforms drops of Chrona's blood into spikes for multi-angle attacks.
- Screech Resonance: Ragnarök's equivalent of Soul Resonance.
- Jet Black Sword: A more powerful form of Ragnarök's sword shape.
