A hidden weapon attached at the wrist that rests along the forearm. Fighting hand to hand against a foe hiding such a weapon becomes far more dangerous than one may first realize. 

Trying to detect magic or identify this magic item fails as its magic is hidden to all but its maker and its wearer.

On a hit against a creature with this weapon you can choose to deal additional damage equal to your Martial Arts die. As long as the creature is not a construct or undead you gain temporary hit points equal to this extra damage. You may use this feature once per long rest.

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

Notes: Damage: Necrotic, Bonus: Temporary Hit Points, Monk and Must take a short rest to fit and familiarize with the weapon, Healing, Damage, Combat, Finesse, Light, Vex