[nitneylion452]

The route you have taken of contacting the principal of the school is a good one, but if that doesn't work, you may need to strike against him. Don't show up to build sessions, don't go to the competition. You also need to make it clear that you don't need him to be a successful team. Tell him that he is not the nucleus of the team (even if that may not be the case.) You have someone who is "drunk with power" because your team gave him the impression that he is absolutely necessary to the building process.