The sword has black markings on the blade and is mostly covered in dirt. The sword also has a heavily ornate hilt with a four-sided guard, a grip with a spiral design, and a sphere for the pommel. The sword is capable of cutting magic with its edges and absorbing other people's magical power. However, when it is used to cut anything else, it is reduced to a blunt sword that uses blunt trauma to inflict damage on the opponent.
The sword's original ability is to absorb spells and then to release that magic in a flying slash. After the sword has absorbed a certain amount of magical power, the black markings on it start glowing with a color corresponding to the absorbed magic attribute. At that moment, when the user swings the sword, it unleashes a flying slash with similar properties as the absorbed magic attribute. Alternatively, it is also capable of being filled with Anti Magic, releasing flying slashes composed entirely of Anti Magic.
Another ability the sword possesses is connecting the wielder to their allies. With this ability, the wielder could draw magic power from their allies over a large distance or could transmit magic and information to their allies.
It has been noted that the sword passively absorbs magic from anyone holding it and is immensely heavy. This absorption ability can be used offensively by impaling an opponent and letting the sword drain the victim's magic power and weakening their enhancements.
- In Tales of the Rays, Asta can use the Demon-Dweller Sword to perform the following strike artes: Demon-Dweller: Flash 「宿魔・一閃 Shukuma Issen」 and Demon-Dweller: Instant Slash 「宿魔・瞬斬 Shukuma Shunzan」.
- Asta can also use both the Demon-Slayer Sword and Demon-Dweller Sword to perform the following strike artes: Demon-Slayer and Demon-Dweller: Rotation 「断魔&宿魔・旋圏 Danma & Shukuma Senken」 and Demon-Slayer and Demon-Dweller: Blade Flat 「断魔&宿魔・剣脊 Danma & Shukuma Kenseki」.
|Demon-Slayer Sword • Demon-Dweller Sword • Demon-Destroyer Sword • Demon-Slasher Katana|
|Bull Thrust • Black Meteorite • Black Hurricane • Black Divider • Black Slash|
|Mirrors Slash (Mirror) • Mirrors Meteorite (Mirror)|
|Liebe • Asta|
|Demon-Slayer Sword • Demon-Dweller Sword • Demon-Destroyer Sword|
|Origin Flash • Origin Flash Barrage • Conquering Eon|
|Protecting Light (Light) • Spirit Light Tree (World Tree)|