Archdevil's Edge

You gain a +3 bonus to attack and damage rolls made with this magic weapon.

Inside the sword is imprisoned X'Arkar, the Lady of Onix, an ancient and powerful Fiend, the weapon has an Intelligence of 20, a Wisdom of 18, and a Charisma of 22. It has hearing and darkvision out to a range of 120 feet. The weapon communicates telepathically with its wielder and can speak, read, and understand Common and Infernal.

• While you hold the drawn sword, it creates an aura in a 10-foot radius around you. When a creatures enter the aura they must succeed on a DC 19 Wisdom saving throw. If they fail, every time they take damage in the area they suffer extra Psychic damage equal to your Charisma modifier. The effects end once they leave the area.
• While attuned to the sword you know how to speak and read Infernal.

When you slay an entity with the sword that is not a construct or undead the sword regain 1 charge. It can hold a maximum of 10 charge. As an action you can consume a number of charge to replenish yourself.

• You can expend a number of charge to heal 1d8 hit points per charge used.
• You can regain expended spell slot by consuming a number of charge equal to double the spell slots levels.

Once per day you can let the Devil consume 3 charge to merge your body with the Devil Soul to gain one of its trait’s. For the next 10 minutes you gain one of the following benefits:

• You sprout a pair of leathery wings, for the next you gain a flying speed of 60ft.
• As your mind merge with that of X’arkar you gain telepathy 60ft.
• The Devil ability to charm and manipulate augment’s your own. When you try to magically charm an humanoid it roll the saving throws at disadvantage.

Curse: This weapon is cursed. A fact that is revealed when an identify spell is casted on the weapon or when you attune to it. Attuning to the weapon curse you until a Remove curse or a similar spell is casted on you. While cursed:

• The wielder of the weapon is unwilling to part with it.
• You read as a Fiend of Evil alignment. 
• If you are healed by a divine source while attuned to this weapon you suffer damage instead of recovering hit points. This damage cannot be reduced in any way. When you suffer this damage you must make a DC 20 Wis saving throw or attack the nearest humanoid until you fall unconscious, or the sword consume a new soul. 

Proficiency with a Longsword allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Bonus: Magic, Damage: Psychic, Language: Infernal, Damage, Combat, Warding, Versatile, Sap