So here's the thing. Empress and Duke had dated back then despite their arrangement cuz sh...

So here's the thing.
Empress and Duke had dated back then despite their arrangement cuz she loves him.
But she knew he didn't love her back.
She knew he loves the emperor.
So she seduced the emperor and married him.
Intentionally.
Did she love the emperor? No.
She just wanted the Duke's.
She had a twisted love for the Duke as much as the Duke had for the emperor