Darkblade of Gisela

Weapon (Greatsword), Legendary (Requires Attunement by a Paladin)

Broken Swords of Gisela reforged into a greatsword by the blind blacksmith Krizdy and enchantress Almithra. The weapon was also infused with the blessing of Amaunator, but after the blessing has faded, it was replaced with a dark force from an unknown entity by the black market shopkeeper.

You gain a +5 bonus to attack and damage rolls made with this magic weapon. When you hit an celestial or fiend with it, that creature takes an extra 3d6 psychic damage.

While you hold the drawn sword, it creates an aura in a 10-foot radius around you. You and all creatures friendly to you in the aura have advantage on saving throws against spells and other magical effects. If you have 17 or more levels in the paladin class, the radius of the aura increases to 30 feet.

Charge. You can cast the haste spell targeting yourself. Once you use this feature, it can't be used again until next dawn.

Protect. When an ally within 30ft of you takes damage from any source, you can use your reaction to reduce the damage to 0. Once you use this feature, it can't be used again until next dawn.

Rebuke. As a bonus action, you can channel dark divine power through the weapon. The next time you hit a creature using this weapon before the end of your next turn, the weapon damage you deal is doubled. Once you use this feature, it can't be used again until next dawn.

Mind Ravage. While holding the sword, as an action, you can cast the psychic scream spell. Once you cast the spell, you can not do so until the next dawn.

Blessing of the Dark One. Sword is infused with the dark power of an unknown entity. It deals an extra 1d6 psychic damage on hits and when you score a critical hit against a creature, it must make a DC:20 constitution saving throw or be stunned until the end of your next turn.