Trahearne is obviously non-human, and given the origins of sylvari I'd say you could consider him an inherently magical being alongside being a spellcaster.

I can go into more detail if you'd like, but whether or not sylvari actually have souls is up for debate. If Leo can see something like that, then he'd either appear to not have a soul or to have something that isn't like what a soul usually appears to be.

Using any and all other eye powers on him is a total yes btw!