Pluto

Pluto was born in 1898, dying of pneumonia in 1920 at the age of 22. at the moment of his death he was visited by a grim reaper. He refused to pass on, wanting to watch over his family. The grim reaper gave Pluto an option, he could become immortal, working as a grim reaper and guiding souls to the afterlife, but in return he had to give up his identity, choose a new name and cover his face. He could not interact with anyone who knew him or could recognize him. Pluto took this proposal in an instant, but he soon regretted it. He attended his own funeral, watched his family mourn and eventually forget him. And eventually he watched them all die, without being able to help them in any way. He quickly became reclusive. During life he was always happy, sweet and polite, a child at heart. He became morose and nihilistic, only existing until the day there were no more souls to reap. He didn't need to be alone. Grim reapers could force deceased humans to accompany them and help with the reaping process as familiars. He soon met Mourning Dove, another person like him who refused to pass on.

Original design:
https://sta.sh/215qo3dzvak5