To be honest, Sora wasn't sure about some of the finer details himself. He scratches the back of his head sheepishly when he realizes how little sense it made. He's not sure if it's the way he explained it or the details themselves, but he knows it's partly his fault it's a little convoluted. Anyone else from the set of worlds he knows would be better at explaining it, mostly, though he can at least explain the Heartless. He supposed he could leave out the Emblems versus Purebloods business for now...

"Heartless are the darkness out of people's hearts, given form. There's a couple ways someone can lose their heart, but there's always a Heartless when they do. They're mostly hostile, though there's a few that won't really bother anyone or even want to play games. Other than, they seek after other hearts, though they can sometimes be controlled. But anyone that can control them is usually pretty bad..."

Usually. Although the only exception he knew of was Riku and that had only been briefly anyway.