Another part of Venom's appeal specifically to the Japanese is that his head when it comes off Eddie, acts as a chibi form obviously, the symbiote can go on anyone making it a self-insert fantasy even more than Spider-Man, the simplistic black and white design fits manga especially, and a lot of manga has a demon type figure inhabiting the protag to kick off the story. Man if Marvel instead wrote new characters who'd use it in unique ways that would be cool. Like an anthology.