Bioarcane Items

The ancient elves crafted potent bioarcane items, designed to ensure the upper class of elves be truly superior. Vallak, Biomancer was first to create these items. They are now used primarily by dwarves with connections to the ancient vaults of the first elves, with modifications to weave metal and gemstones within them.
The magic of these items is unlocked only by attaching them to one's body. This requires a limb or organ be removed before the item is grafted to the owner in its place. Each item requires attunement, and will not function at all if not attuned. These items cannot be forcibly be removed from attunement.
During a short or long rest (specified in the item's description), another creature can perform the procedure of removing your body part or organ and attaching the item to you with a DC 20 Wisdom (Medicine) check. If you decide to perform the procedure on yourself the DC of the check is 25. If the check succeeds the item is attached and you take 3d6 damage that cannot be reduced in any way. If the check is fails by 4 or less, the item is attached but you take 8d6 damage that cannot be reduced in any way. If the check is failed by 5 or more, you lose the organ or body part, the item is not attached, and you take 16d6 damage which cannot be reduced in any way. In special cases noted in the item's description failure to attach the bioarcane item results in your death.
Once the item is attached, it is activated and you can begin to make use of its properties.

Item type

Cybernetic

Items described here are based on work by James Introcaso of worldbuilderblog.me