I Will Appoint You as the Protagonist

I, Seo Si-ha, was reincarnated as a nameless beggar in a typical romance fantasy world.But because my face looks exactly like that of Eos, the kingdom’s royal healing princess, I end up becoming her substitute and enter into a political marriage with the Grand Duke of the empire.So my marriage partner is that cold, blunt, yet handsome northern Grand Duke?
This man is definitely either the male lead or the second male lead of a romance fantasy novel!So I planned to stay by his side only until the story’s real heroine appears.
“You probably don’t know how worried I was about you all night.”
But then, why is he getting closer to me instead of the heroine?On top of that, he’s still trapped in his painful past, suffering from nightmares and isolating himself.
Unable to just watch, I made a decision. Fine. I don’t care whether he’s the male lead or the second male lead.
I’ll make him the protagonist myself.