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

A truly unique piercing sword, a single piece of carved drake bone forms the long, guardless hilt and pommel. Translucent, shimmering blue starlight forms a blade that seems intangible and ephemeral yet is solid and sharp to the touch, shaped more like a longsword than a rapier, being longer and wider than typical, but still as thin as a needle. A ribbon of starlight flows seamlessly from the base of the blade; silky, smooth, elastic, and intangible to all but those who know how to harness and handle the cosmic material. A polished black gem is set in the bone just below the blade, a gleaming tether to draw the energy of chaos from Limbo.

With a form that is halfway between rapier and javelin, the wielder can throw the weapon and make a ranged weapon attack, with a range of 20/40. When thrown, the wielder keeps grasped in their hand the blades ribbon, which stretches to keep the weapon tethered to them. As a bonus action, the wielder can choose to either teleport themselves to the tethered weapon, or to pull back on the ribbon and return it to their hand.

While attuned to the blade and holding it in hand, the wielder is immune to the paralyzed and petrified conditions.

As a bonus action, summon in offhand a cluster of illusory daggers, which I throw in a 30 foot cone. Anyone in the cone makes an int save (DC 17) or take 3d6 psychic damage.

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

Notes: Bonus: Magic, Damage: Force, Weapon Property: Thrown, Damage, Combat, Finesse, Vex