The first thing I notice is that your team is mostly fast and frail, which makes it really vulnerable to Trick Room, especially since you have no way of countering it other than Thundurus's Taunt or trying to OHKO the user. While it's not a great solution, the easiest way to deal with it without significantly changing your team would be to teach Trick Room to Porygon2. That way, if the opponent does manage to get it up, you can just reverse it on the following turn.
Espeon seems really redundant with Gengar and Metagross (especially with a less than ideal nature) - it shares two weaknesses with Gengar, while having overlapping coverage with both. I would consider replacing it with either Cresselia, the standard dual screener (though it keeps the weaknesses) or Rotom-W, which has much better typing and bulk and also helps you deal with rain and Trick Room better.
Thundurus should have Thunderbolt instead of Thunder on any non-rain team; the extra power is not at all worth the drop in accuracy, especially in a tournament format where every battle matters so you can't afford to miss.
I used Scarf Staraptor
on my team in the last Wi-Fi tournament, and I have to recommend trying out Reckless instead of Intimidate. It has enough power to OHKO just about any Pokémon without significant defensive investment, and a KO'd Pokémon is obviously much less threatening than one at -1 Atk, especially considering how many of the top threats in the format are special attackers. But that's largely a matter of preference, both abilities are perfectly viable. If you do end up using Reckless, be sure to give it Double-Edge instead of Return.