Yes, I did beat the Shadow Queen. It wasn't easy, but If you want some tips, go to the Game Help section, and there will be a thread called Paper Mario for Gamecube. My strategy is there. Or, you can look for websites that over tips about boss battles.
"You fools! You''ve messed with the natural ordaaaaaaa!!!"~ The story telling crow from the Grim Adventures of Billy and Mandy.