You must be wondering... What was happening in the demon world while Vergil was out there, enjoying his time with Katharina? Well, many things. But the topic of the moment in every noble house was just one...
The political power he holds.
You see, if he were an ordinary man, things would be much simpler. All he'd need to do was marry an heir to a powerful demon house, and his influence would be guaranteed. But Vergil is no ordinary man, is he? He got involved with not one, but three direct heirs! Something so rare that, just because of that, he was already the center of attention.
Now, add Sapphire to the equation. Yes, the Sapphire. She's not only the most powerful demoness but also his mentor... and his mother-in-law. This puts Vergil in a position no other demon has ever been in...