After Thought

     After Thought is a normal +2 dagger when wielded by anyone that is not attuned to it.  Once attuned, the dagger's special properties are revealed to the wielder.  If the wielder has advantage on an attack After Thought provides a +7 to hit (although in the hands of Vecna it's a +13).  On a hit it deals 1d4+5 piercing damage plus 2d8 necrotic damage.  If the target is a creature, it is afflicted by entropic magic, taking 2d8 necrotic damage at the start of each of its turns.  Immediately after taking this damage on its turn, the target must make a 20 DC Constitution saving throw, ending the effect on itself with a success.  Until the creature succeeds on this save, the afflicted target can't regain hit points.  Furthermore, while afflicted in this way the creature begins to lose parts of its body to the aforementioned entropy--first fingers and toes and hair, followed by limbs, and eventually more vital body parts.  Each time one of these effects is suffered by the target the wielder gains 1d4+4 temporary hit points, as if the spell False Life had been cast, and this benefit stacks with each creature that is under the entropic magic caused by After Thought.  

     After Thought comes with a price and the following detrimental properties accompany the blade.  While attuned to this artifact the wielder is unable to smell.  Additionally, the wielder's physical appearance becomes more and more skeletal the longer they are attuned to the item.  

Notes: In order to attune to this dagger one must kill an innocent with it.