Seduce the Villains Father

After being in a bus crash I woke up to the world of my favourite web novel
Not only that It was before the protagonists were born to their parents world
To stop the incoming multiple bad events
I tried to prevent the kidnapping of the sister who is pregnant with the female lead
But I got kidnapped instead
Its depressing to be kidnapped but my body couldnt handle the mana and became a sunfishlike state
But if I am next to the emperor who kidnapped me my body becomes normal
Right The way to save that man from marrying a witch and getting killed by his son and for someone who is vulnerable to mana such as myself to live is for us to get married