Responses
No the destiny of bighead is related w rourou. As rourou has named him and changed his destiny already. But great grandpa meant that bighead's naming can be only done by the person who named him and gave him this destiny (aka our rourou), anyone besides rourou tryna name him will lose their good destiny (which bitch aunt will lol). Bighead is now connected w rourou so no one can harm him.
Well, its good they listened to the grandpa and didnt give him another name I think if they did it would affect him in some way, maybe his fortune would be bad since he was not supposed to be born but RouRou helped him. Its clear he cant be named until he meets RouRou, otherwise something bad would happen.