The Beginning After The End by TurtleMe

He was a cold and brutal king in his past life and also an orphan. And in this second life he wanted the innocence of childhood and sylvia also wanted him to experience what being a child with a loving family is like. But his childlike act is actually just a ruse which he himself, and his father mentioned. "When you acted like a child it felt calculated and out of place" (I'm paraphrasing btw since I don't remember the exact phrase)

And don't worry starting from volume 8 his true nature as the cold, brutal king came back to life in volume 8 where he doesn't have to act like "Arthur". Tho I still wouldn't call him completely heartless since he became a better person after his reincarnation. Anyway I'm bad at explaining shit so it would really be better if you give it one chance and at least read to the latest chaper.

nothing has been resolved regarding that. Put me off reading. I'll just come back for the Nico comeuppance chapter I think, if that ever happens

true, but he doesnt brainwash her,but cecilia is still learning about the world . in the latest chapters she finds out about his cruel nature and the restrictions placed on her, i think its only a matter of time she leaves agrona and joins arthur. but i think arthur is better suited to caera so i dont care either way