Arm of the Battle Mage

This item replaces a lost hand or arm. While the prosthetic is attached, it functions identically to the part it replaces. To attune to this item, you must attach it to your arm at the wrist, elbow, or shoulder and hold it their throughout the attunement process. Once you are attuned to the item it cant be removed until you unattune from it. 

While attuned, the prosthetic provides these benefits:

• The prosthetic is a fully capable part of your body.
• The prosthetic is a magic melee weapon with which you are proficient with. It deals 1d8 force damage on a hit. It has the finesse property.
• You gain a +1 bonus to AC
• The prosthetic can be used as a spell casting focus and you gain a +1 bonus to spell attack rolls and to your spell saving throw DC.
• The Arm of the Battle Mage has 4 charges. It regains all charges after a long rest. When you cast a spell of 5th level or lower with a casting time of one action, you can expend one charge to change the casting time of that spell to one bonus action for this casting.

Notes: Bonus: Armored Armor Class, Bonus: Spell Save DC, Bonus: Spell Attacks, (requires attunement by a humanoid that can cast spells)