Revenants - Their mission is to bring final death, many creatures or humans try to claim immortality. A Revenants job is it to take it from them. They are initially created to complete one hunt. They are bound to a Memento Mori. Old age is never a reason for becoming an Revenant, there is usually an exceptional/odd reason which would not constitute a 'normal' death in the same way dying of age is. A Revenant is different from a human in that he has the resilience of the dead. Cold or sickness won't affect him. Other than for example a zombie, a Revenant has the same character as well as the same feelings and memories as the human it once was.

Momento Mori - An immensely powerful being created specifically for the Revenant based off of how they died. They funnel their powers through them so they may do their work. The form, personality, attributes and powers of a Memento Mori can vary heavily. Some can be humanoid, others animal like and even geometric. They often communicate with their Revenant, as well as with other Revenants or Memento Moris, but they generally do not do the latter two unless required.

Level Graded Spirit - Within the global magic community, there is a general model to help categorise spirits. Ungraded spirits are weak, mostly just fragile memories which cling to places and cannot impact the material realm to any degree, while a Graded spirit can have influence over the material realm and even greater power over the supernal realm. These grades go from 1-10, with 1 being something like a self-aware poltergeist and level 10 spirit being beyond manifestation, more akin to an 'aware concept' than anything else. A Revenants Memento Mori is a 6 on that scale.

Magic - It exists in this setting, as you can imagine, but it's generally kept very well hidden from the public.

Immortal Beings - It's in the name. This classification is about as broad as the Level Grade model for spirits, powerful vampires and magic users being among them.

Name: James "Jimmy" Meyers

Age: 24

Appearance:


Nationality: American

Personality: Jimmy is actually a very nice young man, he cares deeply about his friends, since they are the only possessions he ever had. He is however incredibly lazy and always up to no good. He lives in the today and never even thinks about tomorrow.
Their is a side to Jimmy that is incredibly dark, he is willing to go incredible lengths to get what he wants, and could not care less if someone might get hurt. He feels left alone in the world and mostly blames his failures on society, he can be self-ironic however.

Background & Death: Jimmy was born to a poor family in Queens. His mother loved him dearly but died when he was 9. Then his father started drinking. There were only a few times when Jimmy's Father was abusive but being at home was still a torture for the young Jimmy. The first time he took drugs was with 12. It started with alcohol and weed, later Crack, Meth and Heroin. Jimmy took them all. He dropped out of school with 15, because he never showed up there.
From then one Jimmy lived on the street. He abandoned his home and his father, who never really searched for his son after that. Jimmy did odd jobs for everyone who would be willing to pay, he sold his body, cleaned buildings, begged and stole money. All to get the next hit.
It was a wonder he even made it to 24. Jimmy was a wreck he died of an fatal syringe of Heroin.

Name: Black Tar

Represents: To give up one's own live just to have a moment of euphoria. The slow and self inflicted death by addiction and drugs.

Appearance:


Personality: Black Tar is abusive and cynical. If he speaks he puts Jimmy down in every way he can. This aggressiveness is a product of Jimmy's own self pity and regret.

Abilities: Poisonous Touch- Jimmy's veins seem darkly, even black when he touches someone and fills them with all the pain drugs can do to someone. A single, short touch, of one or two seconds can give the victim strong symptoms comparable to drug withdrawal. Up to five seconds severely paralyze the victim and weaken him. He might not even be able to hold himself on his feet. Over ten seconds of exposure to this ability will kill a person. Like a overdose.

No place like home- The only thing that has always accompanied Jimmy in his short live was the street. Now a city can be Jimmy's strongest companion. He can go into one smelling dark back-alley and come out of another in a matter of seconds. Street-dogs and rats that live from the garbage of the humans will flock to Jimmy and defend him. Doors of old, abandoned buildings seem to appear and open just for him.

It's the closest I could get for what I was looking for.

Inspired by:

Take a wild guess at her cause of death.