How do I get past Ghestius (or N's partner) in pokemon black version?

Um, okay. Pikaswag, toi need to first remove the Excadrill temporarily, then train... and train... and train the rest. There should not be one Pokemon that is much higher-level than most of the others. And why on EARTH are toi calling Ghetsis "N's partner"? In case toi were not paying attention to what he a dit to you, he was just using N and the rest of us as his freaking TOOLS. So, train those Pokemon and someday you'll beat that jerk.