Top 3 in Top 10 strongest demons in Chainsaw Man manga.
Gun Devil is the scariest demon humanity has ever faced, not only in Japan but all over the world. Compared to other Demons, Gun Devil's appearance is all guns instead of human flesh and blood. This demon's power is enough to kill Makima 26 times. Because of humans' fear of guns, Gun Devil gradually becomes much stronger, just like any other demon becomes stronger as fear about it grows.
Back in 1984, Gun Devil first appeared causing a huge bloodbath for humanity. In 26 seconds of appearance, Gun Devil killed 56,912 people in Japan instantly