
i think the imortal in this comic different with what you think. it's different from immortal being like vampire who stop aging. i think it's more like they are not immortal but have a frightening revive ability, more like zombie with additional logic, and regeneration ability and minus rooten body. for the rest, well who know how the author thinking, but if we use our world logic, maybe they will die when reach climax of their soul. who know... ╮( ̄▽ ̄)╭

Can Ajins age? I think Time has stopped for them after their first death experience but if they can age, then iam sure they will turn back into the age they died the first time every time they die. So lets say someone dies with 15 and comes back, lives a happy live until 90 and dies again then he will wake up as a 15 year old. But thats just my own theory. So maybe Satou just died as an old man???
I have a question: why Satou is an old man? I mean, demihumans are immortal, right? They cannot be killed or die by illness, so I was wondering why Satou keeps aging. (I ask about him cos is the oldest one, but the same goes for all the adult demihumans xD) That means they have limited time like if they were 'mortals'? What do you think can happen when the body of a demihuman is too old? It reverses its life like those arctic jellyfish? Lol.
Crazy thoughts I have in the middle of the battle ╮( ̄▽ ̄)╭