It's awfully convenient that most of the royalty across the various continents have personal access to a door. But at least the doors don't discriminate and show up for all others too in generally accessible places.

That said, Adelheid has certainly become the Queen of Diplomacy lately. At some point her "pauper's disease" (pneumonia?) will heal itself (or whatever it is exactly, but it isn't asthma as wikipedia implies, because she coughs up flecks of blood occasionally in season 1). When it does, she will be a powerful force in the court since she already knows literally every noble's personal tastes and has them all memorized. Or she'll be married into the Country of Sand, heh.

I am a little surprised that the Demons are peacefully aligned with the Empire after the war, because Aletta got such awful treatment before she found a door. Prety sure that Aletta and Sarah "Mince Cutlet" are both from the area governed by the Demon Princess.