You have a +1 bonus to attack and damage rolls made with this magic weapon. As a bonus action you can cause the individual bones of the blade to separate and become a whip like structure. Changing the weapon rom sword to whip or back to a sword takes a bonus action. As a whip the weapon has reach to 10'.
Proficiency with a Longsword allows you to add your proficiency bonus to the attack roll for any attack you make with it.
This weapon has the following mastery property. To use this property, you must have a feature that lets you use it.
Sap. If you hit a creature with this weapon, that creature has Disadvantage on its next attack roll before the start of your next turn.
Notes: Bonus: Magic, Damage, Combat, Versatile, Sap