I just beat Tate & Liza for the Mind Badge in Mossdeep. It took a while because they kept using Hyper Potions, but I did it. All I needed was my L30 Manectric to paralyze both their Lunatone and Solrock, then I switched in my newly evolved L18 Mightyena (Hound). With Hound and my L28 Absol, I took down both of their L42 Psychics. I just caught that Absol at L27 and it rocks.