Well that ended rather nicely for everyone involved, except Elisabeth.
Sadly, I don't think it will end well for Demetrios Sideros as the Germans are definitely going to intervene in Elisabeth's favor now and that has the makings for a very bloody war. I'm also under the impression that Maria of Agra will probably still rebel with the Eastern Armies to put one of her children on the throne. So either way I still think we will have a civil war, unless I'm completely wrong and she is perfectly fine with her children losing their rightful inheritance.
Isn't Odysseus head over heels in love with Maria? I'm not sure how mutual that feeling is, but at the very least she seemed very kind towards him. And Demetrios seems to be aware of Odysseus' affection and even suspects he wants to marry her. Maria marrying the Kaisar would be quite scandalous, but it could secure some support and security in the east once the Germans attack. It would also complicate things in terms of succession with Andreas' illegitimate children still being around, and now as step-children of the Kaisar and eventual Emperor.
Then there's also the moment Maria shared with Andreas before he died. Maybe he shared his wishes for succession with her. If he said he wants his close friend Odysseus and almost-brother to succeed him over his bastard sons, I'm not sure Maria will act against that. Unless of course he wanted one of his illegitimate kids on the throne, in which case she might rebel regardless of any friendship to Odysseus.