...Zapfish powers everything because it's a sort of ritualistic belief? Like the Fax Machine Shrine (which I'll get into in another post, they're devoted. So when the Octolings steal it to try and get back home, Cuttlefish has you ANNIHILATE them. He's using the instilled fear of Octolings combined with the devotion to the Zapfish to make you think you're saving the world. It's just dirty work.