1.

When this "black belt person" is ready to give it to you, you want to start at a good distance away. You wait a second then try and react to his move and make him miss. If he doesn't make a move you try and tackle them from which ever point they're vulnerable at.

2.

By now they have you pinned down or in some type of lock, such as a headlock. At this point you want to get out of it and curl into a ball or try and get a little away and so they can inflict as little damage as possible.

3.

Again, they will get you in a lock again. At this point call for your mom and tell her to get your brother off of you.