There isn't a definitive mythological "grim reaper" or "Death" in my world, but in this world where weird spirits frequently interact with the world, there is a spirit that could be considered sort of a "reaper" character that's obsessed with the dying called the Mystic.

It's not an omnipotent spirit that harvests every dying soul in the world or anything like that, but it can detect death and wants to be there for the show. What makes the Mystic interesting is that it actually seems to be 2 beings in one comprised of a Faun and a Satyr: The Faun is basically a humanoid creature, basically like a traditional faun carrying a bow and arrow, who is swift and serene, with nothing that visibly threatening about it. The Satyr, however, is basically as Lovecraftian it gets; being just an incomprehensible "color" that's the epitome of "Oh god what is that thing run run run."

But the thing is that anybody viewing the Mystic can only see one side at a time, and it's entirely based on perception. Those who fear death and try and run away from it only see the Satyr, who will chase them for eternity, but those who don't, such as seeing it as an inevitability, or are completely unaware of it, see the serene Faun. It's not like a shapeshifting thing, it's all perception; if 2 people were locked in a room with it they could potentially see it as two completely different things at the same time.