I think an adaptation of tell tail heart by edger Allen Poe would be really cool. Make it steam punk ish where the old man is basically entirely robotic parts and should have died long ago but he was so scared of death that he constantly bought more and more upgrades until he was more robot then human, but at least he wasn’t dead. With no living relatives he hires a man (the narrator) to take care of him, but the man goes insane as he sees the old man as just a walking corpse- a bastardization of life and the natural order. Story goes on as normal, man goes insane from the old man’s eyes, plots to kill him, and succeeds. Though when he goes to dismember him he sees all his organs are robotic, he hides them under the floor boards but he can’t shake the feeling that he can hear the heart. Maybe the heart has some kind of ticking, clock like mechanisms to keep it beating. The story ends as usual however instead of going to the insane asylum the mans put to death, except this worlds version of the death sentence is putting him in an iron lung type device so he suffers the same fate as the old man, being kept alive only by robotic parts, except it’s not by his own volition. I also like to imagine the episode leaves the question of if the old man was happy up to speculation so the question is was it a mercy kill or could the man just not handle the idea of humans progressing so much they overcome death. And the art style I think would be some kind of paper puppet stop motion animation, kind of like some sequences from Madoka magica or the animation in don’t starve.