You've got a great premise, so no issues there. I'm just a bit confused about the prologue and its relevance to the story as a whole. Perhaps you have a payoff regarding its events, but this is just what I know from reading the chapters you have available at the moment.
I think the prologue should more overtly center around Jon's transmigration into the prince's body (unless of course there's a twist involving Everard and Jon) so we can learn more about who Jon originally was. The thing about an Isekai premise like you have is that the transported character's origin point is just as important as their destination.
The world that they came from will inform their choices and viewpoint as they interact with their new circumstances. I know it's early and he was only just coordinated, but that's just something to think about. It should especially cause issues if he's from a completely different rung of society than the person he's replacing.
That's just my 2 cents. Also, would you mind checking out the 1st chapter of my web comic? I just did some major revisions to it and I need a 2nd opinion. It has a similar subject matter to your own story, but instead takes place in a sci-fi setting.