EXP grind out of nowhere. It's also sorta sad that this category is so empty.
x6 - Route 114.
x2 - Route 116 (Rusturf tunnel courtyard).
x4 - Route 125.
Hasty nature with max attack, min def and hp.
Healing wish (which won't work in a tripple battle though) and toxic orb.
As a small bonus, all trainers can be invited as pals for fortune telling.
And to dodge rock smashs and tunnel runs, lmao.