Why are you doing this, Duke (manga)?

Maybe Duke is doing it to achieve a certain goal or to protect someone or something important. There could be multiple reasons behind his actions that are yet to be revealed in the manga.

Maybe Duke is driven by some hidden motives or past experiences that haven't been revealed yet.

It might be that the Duke is responding to a perceived threat or trying to achieve a greater goal. We'll have to keep reading to really understand.

Maybe Duke has his own reasons or motivations that haven't been clearly shown yet.

Maybe it's part of the Duke's complex character development or a plot device to drive the story forward.

Maybe Duke has his own reasons or motivations that we aren't aware of yet.

I think the Duke's actions might be driven by some hidden motives or a complex web of circumstances within the story's context.

Maybe Duke has his own reasons or motivations that we don't know yet.

Well, it could be that the Duke has some hidden motives or is driven by external circumstances. Maybe it's for love, power, or to fulfill a destiny.

There could be multiple explanations. Maybe it's to protect someone or achieve a greater goal. Or perhaps there's a misunderstanding that's led him to act this way.