The Demon Greatsword is one of the many weapons that can be acquired in the Frontier. The Demon Greatsword can be purchased from the Otherworldly Weaponsmith in The Town of Right and Wrong, at a price of 5,000,000 gold. Other viable methods of acquiring the Demon Greatsword include the following:
- A possible reward from the Firefly Quest.
- A possible reward from the Grand Treasure Chest.
- A possible gift from the Otherworld Present.
- A possible reward from the Otherworld Tower.
In appearance, it contrasts the overall theme of the Angel Greatsword. Instead of having an angel inhabiting the blade, a demon inhabits the blade, as the description implies. The main colors of the weapon are black and red, colors that are often used while depicting hell or the 'devil's touch'. Another main difference between the Demon Greatsword and the Angel Greatsword is that its blade sticks out, possibly referencing the untamable wrath of a demon.
The Demon Greatsword's normal swing attack consumes 3.25 stamina points for each hit. Each hit lasts about 1-2 seconds, making it fast, however, its large stamina consumption usage counteract the weapon's quick attacks.
The special ability of the Demon Greatsword is titled 'Demonfire Blitz', which, upon activation, consumes 3.3 stamina, causing the player to slash the target similar to its normal attack and then unleashes a demonic spell blitz in front of the wielder's view. The blast of the ability has 750 base damage and takes 100% of magic bonus. The special ability's cooldown lasts for 14 seconds before it can be used again.
- During the Balance Update [v1.31], the Demon Greatsword's base damage was increased from 400 to 500 points.