Revelations from Patch 7.3: The Promise of Tomorrow

[Cleretic]

I'm sure there are other things they can do. My prediction is that they can use things like the Azem Crystal or the Key, since the signature of their souls is the same as ours.

There's actually no evidence that other people can't use the Azem crystal, nobody else has tried.

The key is even funnier, because we actually have no evidence that we can use the key! We've never tried. In fact, we also know that Preservation can and has used it, they're just not very good at it.