[SPOILER] Alexander von Brennenburg...

[cantremember]

Maybe the term is different in my country, but I've always known an uncle to be a sibling of either of your parents.
An aunt's spouse is, at least for me, not an uncle.

And I think it's more likely the reference is to Daniel, as he is the one who made the archeological finding of an orb, whilst I think Alexander's orb, I don't remember where he got his actually.