It's the name of a video game released in 2015 although I found a website (apotheon.org) when searching Wayback machine (the game's actual website is apotheongame.com).
The title of this post made me think that you were a immortal confused by the evolution of language.
vvilld@lemmy.world 1 week ago
www.yourdictionary.com/apotheon#K7byWihCcMgSUeOb.…
Yes, it seems to be a real word in Ancient Greek, although it didn’t seem to have any special significance beyond it’s definition.