Hi, onepiece! It seems you know the teambuilding basics, but a few suggestions:
1. Excadrill - Why X-Scissor? Run Iron Head over X-Scissor. Instead of Rock Slide, run Stealth Rock.
2. Tyranitar - I would suggest Mega Tyranitar, as Mega Charizard Y's Drought takes away the Sand. Earthquake/Crunch is good. I'm not understanding the purpose of Iron Head. Run Ice Punch or Dragon Dance instead. Also, Replace Rock Tomb wit