So, I'm about to fight Tate and Liza. One of my Pokemon in the double battle will be Tsunami the Swampert (Water Super Effective), however, I don't have another good match. BLR the Pelipper has super effective Surf, but it's vulnerable to their Rock STAB, and Bisque the Breloom, who has super effective Giga Drain, is weak to their Psychic STAB. So which one should I use?
(I also have a Camerupt named Victory, a Magneton named Fridge, and a Lunatone named Cheetos, if you think I should use one of those.)