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

Unluck. If the sword is on your person, you can call on its unluck (no action required) to force anyone to reroll one attack roll, ability check, or saving throw. They use the lower result. This property can't be used again until dawn or until you roll a critical hit with this weapon.

Bestow Curse. The sword has 3 charges. While holding it, you can use an action to expend 1 charge and cast the [Tooltip Not Found] spell from it. The sword regains its charges at dawn.

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, Control, Buff, Combat, Versatile