Sorry if it offends but this is inspired by the Bible stories of Samson. This would be a living scalp with growing hair that when worn will fuse onto you and enhance your strength at increasing increments as the hair gets longer. You can trim and style it at a cost of some of that strength or let it grow unchecked to the point where it covers your body like a cloak and even trailing behind you as it drags on the ground like a long cap in exchange for the increased strength.
BOX OF TORMENT
This strange and mysterious box records the last thoughts of any departing soul in it's proximity. If someone owns it and kills an enemy, the trauma and agony of the departing soul will leave a "trace" inside the box witch will capture it's final painful moments in the form of the last thing the soul was able to process. It can be a scream, a curse, a cry for help to the gods, the though of a loved one, anything really... Once captured and stored inside the box, it can be heared, among many others that the owner would kill, in the forms of hauting disturbing whispers just by activating the box.
NEVERMORE (well technically this is more like Baron Aoric, in the sense that it would be a cosmetic NPC so not an item)
A demon that possessed a raven, looking unusually big and ominous. It follows the player, eating scraps of the souls that he/she slains before they leave this world (like a normal raven would do with corpses), resting on the shoulder when not in combat. When the player enters combat it would fly around or stay on some tree/roof commenting the fight (so yeah it would be a talking npc like the baron). It would talk outside combat too of course, but being a demon the player should be very careful to trust everything it says although sometimes it may say very interesting things (demon are supposed to be very knowledgeable after all). I imagine it to be pretty sassy and very fond of mocking others (even the player).