"No, I don't think so. I think the question of physical possibility is pretty much settled. Something's up there, and it's greater than any of us are alone", the stranger remarks. "I think there are far more interesting questions than that. Like, could something down here become its equal? There is a man I... have heard of. At least once, he considered himself the logical endpoint of all existence. He thought himself powerful enough that someday, he'd devoured every soul in existence. So suppose he did that. Would he be able to overthrow the King? What would happen if he did? Would it just end the world, or would it be remade in his image?"

"Or lets approach this from another angle. You said the King occasionally takes one of the Shinigami to him. That implies there's a way to reach him, but is it possible against its will? It'd be odd if, in all these years, no-one's ever tried. What became of them, huh?"
The stranger lays down on his back and yawns. "I know you don't have the answers. But have you considered finding out? If you don't have any unfinished business down here, what else would be more worth your time?"