It's okey guys. Thank you for helping with this. At the moment, I just think that I need to let him live, sort off. After all: he is a ghost or at least look like one.
The first sim that has found immortallity without eating Ambrosia. I should be happy maybe.
I still leave this topic open, for maybe a miracle wonder that will solve this. Of course, if I find a solution I will write that here to.
This thread is a bit old but in case the problem is still persisting...
Hm, it probably wouldn't help any with your family cemetary, but you could try moving him out and leaving story progression on (unless you can't/don't want to)... sims tend to die quite easily that way. :p Or just move him out and try killing him in a fire or something when he visits your house.
Or- try make him a mummy (if you have WA). Or have him travel to see if it fixes something; in any case, you could travel to Egypt and have him get cursed by a mummy.
And then let him die... actually, I like that idea (and not only for the evil reasons). Direct, more instant death seem rather fruitless so maybe something more similar to death of old age would work better?
Or just leave him rotting in the basement for a few decades. No one'll have to know about the strange immortal sim-man in the cellar... unless it's in ghost stories of course.
OR (this word is, literally, gold), you could just move him out, and/or delete him, and pretend he never existed. What, an immortal sim?
What immortal sim? *innocence*
It's rather noticeable I've been consuming way too much sugar on way too little sleep, isn't it?
I'm so evil. Now instead of forcing my sims to give birth to 100 babies and take care of all of them for a thousand years, I think about killing them! It's just horrid...