Kurikara (5e Equipment)
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Weapon (longsword), legendary (requires attunement by a creature related to demons in an important way)
The Kurikara, or demon slaying sword is a legendary blade with the power to kill and contain demons and their power. The sword was primarily used to contain the demonic power of Rin Okumura, a son of Satan. When unsheathing the blade the used is fueled with the blue flames of Satan and their power exponentially increases. However there is a risk as the flames can potentially devour and disintegrate the user if the user get overly emotional or simply loses control.
This sword can be wielded as a magic longsword that grants a +3 bonus to attack and damage rolls made with it.
The weapon has 20 Charges for the following properties. It regains 3d6 + 2 expended charges daily at dawn. If you expend the last charge, roll a d20. On a 20, the sword regains 1d10 + 2 charges.
Spells. While holding the sword, you can use an action to expend some of its charges to cast one of the following spells (save DC 17) from it: burning hands (1 charge), continual flame (2 charges), fireball (3 charges), fire shield, flame strike (5 charges) and investiture of flame (6 charges).
Curse: Burning Rage. Whenever you start your turn wielding the sword or after casting a spell from it, you must make a DC 10 Wisdom saving throw, or enter a rage. Every success adds a +2 to the DC, up to a maximum of 24. A good, chaotic good, or lawful good aligned character has advantage on this roll. While raging under this item's effect, you cannot cast spells by any means, or concentrate on them. In addition, you must make an attack against the creature closest to you in every turn. In addition, at the start of each of your turns, you take 2d10 fire damage.
At the end of each of your turns, you can make another saving throw to end the rage. On a successful save, the rage ends and the you suffer 1 level of exhaustion for each turn raging, up to 5. On a failed save, the user continues raging and the save DC decreases by 2. The rage also ends if you fall unconscious and suffer 1 level of exhaustion. Either way, the save DC resets to 10 after the rage ends.
Attuning to the sword curses you until you are targeted by the remove curse spell or similar magic; just dropping or losing the weapon fails to end the curse. While cursed, the sword will return to a place within 5 feet of you if you try to drop it or lose it.