I'm going to hide my brother's xbox because of his crazy fortnite addiction
Do you think he'll ask for it back?
Yes, but he won't ask for it back in front of our parents because they won't allow him to play.
Although it is reasonable to be concerned about your brother's behavior if you think he is addicted to a video game, hiding his xbox is not the right solution. Talk to him about your concerns instead, and if he won't listen, tell your parents why you are worried.
I don't want to talk to him or listen to your family friendly preaching.
It is nice that you are worried about his addiction, gaming addiction like other addictions are bad. But you could get in trouble for taking his xbox, and since your parents don't know, they might misunderstand. It would be better to let your parents deal with the situation.