Responses
Safe from what Cesar considers unsafe. I'm not by any means agreeing to his methods but it's explained in the earlier story his way of addressing care is very different than the social norm. In his mind no one else can care or love MC as much as he can and no one will either. His obsession and love is so intoxicating that he cannot imagine any other way than what he's been taught. If that makes any sense.
After all that Caesar is scared of losing him. He has a shit way of showing it but he'll destroy the world if it means his only love in the world remains alive even if a little hurt or broken at the end ...it's to keep him safe