Alright I've made Nature and ability changer NPCs (I'm not charging shit for it like the other anon, but you'll probably get a sloppier job in turn)
NPCs on the left change to offensive (adamant, modest, timid, jolly), defensive (bold, impish, calm, careful) and mixed (brave, naughty, rash and naive). That should cover everything you need. Scientist on the right changes ability to HIDDEN ABILITY only, it doesn't work it your Pokemon already has its HA. The scientists will change your FIRST Pokemon in the party, if it's fainted, it will go automatically to the second, so be careful.
http://www.mediafire.com/file/s4kj71lt3yx4cdt/Map160.rxdata/file 