Responses
It may be that or the novel detailed him poorly whereas he really did all what he did intentionally, the destruction of the empire etc, coz' honestly just look at the way he's treated poorly. We have seen such character in many villainess manhwas where og FL is usually a two-faced bitch. So I don't find it that weird, maybe it's really his personality
Could the prince have been regression? Like went back in time? He seems to know so much? But I think I'm wrong because he didn't know about the treasure...idk