So Where Is Thresh's Soul At?

I thought I knew the answer to this one, and the answer was "it's in his wraith body." That's the standard for Shadow Isles ghosts, plus his death animation shows his soul getting sucked out of his body and trapped inside his lantern.

But then Senna came out, and one of her lines is something like "Hey Thresh I'm pretty sure I saw your soul in the lantern and it's a wretched loser lmao".

So where_ is_ the darn thing?