hi, I am currently at the pokemon world tournament, my pokemon are around level 30. Last person is the team plasma lady and she has this magneton that keeps 1 shotting my guys. I have a sandile- level 16. How do I level him fast at this point in the game

world tournament?? Do you mean pokemon league?
You said Plasma so I assume you're in black and white?

If you are, get a lucky egg and go back to an earlier point in the game.

he's talking black/white 2 not 1

easy way to just to use him in battles where you'll be faced with higher level (since xp is scaling in gen5)

Ahh 2. Haven't played those, yet. Thanks.