"I said," Thor says thoughtfully, "that folk come from many realms, and many worlds. As you've seen, some come also from death."

"They're guests as any other. Not shades nor hauntings. If their souls differ from living souls, 'tis too subtle for my eyes to see." Which is entirely possible, honestly. Thor is not exactly the best at perceiving really subtle metaphysical and magical stuff. "If he tasks you, it's as one human may another."

So presumably without magic or binding curses and stuff, from what he's seen of Harry Percy.