I have a really good one: Get a lv.2 Probopass with Pain split (BP move). Have it have Ablity Strudy, after the foe attacks, it will most likely have 1 HP, use pain split to fully heal yourself and slightly damage the foe, a combo with this is to toxic the foe and use a 'slow' volt switch or u-turn, then repeat the above steps, this slowly and effectively and painfully and misrably and epicly and... wait, i don't think 'epicly' is even a word, anyways, so it kills the foe slowly and effectively and... well, you get the idea. Another trick is to keep doing this until the opponent is weak enough, then switch in to a lucario or something and extreemspeed that Pokémon.