Go back on Route 1 and get that Joltik(level 30). Train it in Vanhanen Labyrinth, with all the grass types and Girafarig it will be able to pretty much do it's own battles starting at level 40. You get A LOT of Sp. Att EV's in there too, which is great. Use the castle for healing and badabing badaboom you have a Dark-type MURDER MACHINE (her field boosts Signal Beam, Galvantula is fast, it will plow through her harder than Bennett ever fantasized of doing)