This item replaces a lost arm. While the prosthetic is attached, it functions identically to the arm it replaces except that it allows your unarmed attack to deal 1d4 bludgeoning damage instead of 1. You can detach or reattach it as an action, and it can’t be removed against your will. It detaches if you die.

A folding silvered longsword is built into your arm and is inseparable from you. While extended, it seems to be a solid blade.

As a bonus action, you can retract the armblade into your forearm or extend it from there. While it is extended, you can use the weapon as if you were holding it, and you can't use that hand for other purposes.

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

Notes: Set: Unarmed Damage Die, Versatile, Sap