Okay so what if Blackbeard is depressed and irritable and bored out of his mind by piracy but trapped in his own myth-making bullshit and kind of willing to die as long as it would be briefly interesting and then an alien ship crash lands and one of the aliens winds up floating in the sea and it's this weird slick oil spill mass of black-rainbow-void and Blackbeard sees it and knows it could kill him but fuck, what a way to go, so he jumps in headfirst and instead of dying he feels this electric, too-intense sensation like exploding but backwards and suddenly there's another voice in his head and it's saying, HELLO. GOSH. DID YOU KNOW YOU HAVE THE MOST EXQUISITE LUNGS?
And obviously the voice that's the alien that's Stede doesn't know shit about shit when it comes to Earth and humanity, but knows that it can correct Ed's various aches and bones that didn't set right and joints that aren't as young as they used to be, and does so not as a trade or a bribe but just because, YOU SHOULDN'T BE IN PAIN, like it's as simple as that. And it loves dressing up with Ed and curling its tentacles into Ed's beard and helping Ed intimidate people and generally just having fun frolics together, and slowly slowly slowly Ed starts to feel like maybe it's not weak to want something more than hollow pain and survival.