This rapier is thinner than any other you have seen, and is known as a needle due to the lack of guard or pommel. It feels as light as a feather, and with practice becomes almost an extension of your arm.
As an action you can teleport up to 15 feet to an unoccupied space and make a melee attack with this weapon. On a successful attack you deal an additional 2d8 piercing damage.
As a bonus action you can slash through the air, creating strands of mithral that are so thin they can cut with a gentle touch. Choose three 5-foot cubes within 15 feet of you to create these strands in. The next time a creature moves through these cubes they take 3d4 magical slashing damage. These strands last 1 minute, until a creature moves through them, or until you use this feature again.
Web of Mithral
Once per short rest, as an action, you can begin an intricate slashing pattern, filling the space around you with writhing mithral strands. All creatures of your choice within 15 feet of you must make a DC 18 Dexterity saving throw, taking 8d4 slashing damage on a failed saving throw, or half as much on a successful one. Additionally, any creature that moves within this radius before the beginning of your next turn must also make this saving throw.