Looking for a Story

Hello everyone,

I am looking for a story where the protagonist meets death and I believe she wants to borrow/share his body for a period of time. Part of the plot is that, while sharing his body with death, they meet another person (named something like 'delusion' or something similar), after which he slowly changes and things around him start to decay faster.

That is all I really remember at this moment, sadly. If anyone knows which story this is from, I would greatly appreciate some help!

Thanks :)