Not a soul that he might be able to identify as what he's used to. He can likely see something in there, but it would be somewhat...strange. What that looks like is up to you (your canon, your knowledge, your call), but yeah. Strange shit.

Headspace and barriers aren't possible, but if he was able to sleep and enter a magical soul haven, he could similarly see the existence of her being there, though again it would look like some funky stuff, likely unseen before based on his canon. So it does exist, but it's still some unattainable stuff. He's free to report on some details of what he finds, though!