Arcane Dragonshard Enhancable Arm

This prosthetic appendage was developed by artificer Bug, specifically for his friend Capheus. To attune to this item, you must attach it to your arm at the wrist, elbow, or shoulder, at which point the prosthetic magically attaches in place of the appendage it's replacing.

While attached, the prosthetic provides these benefits:

• The prosthetic is a fully capable part of your body.
• You can take an action to remove the prosthetic, and it removes itself if your attunement to it ends. It can't be removed against your will.
• The prosthetic is a magic melee weapon with which you're proficient. It deals 1d8 force damage on a hit.
• The prosthetic has 3 charges and regains 1 of its expended charges daily at dawn. When you hit a creature with a melee Attack using this arm, as a bonus action you can expend one charge to deal 1d8 lightning damage to the target, in addition to the weapon's damage. 
• The prosthetic can hold Khyber Dragonshard in a slot above the hand. When powered by such dragonshard, amount of charges, damage delt when expanding a charge is increased depending on dragonshard's size, quality and being bound by the shard (if there is one). Damage type also changes depending of dragonshard's prisoner. 

Notes: Amount of charges can be increased by Khyber Dragonshard inserted, by a creature missing a hand or an arm