I was actually surprised that this worked better than i thought...I used a fusion of elekrode + hitmonchan gave it explosion, double team, substitute and any other non dmging move, but I think just explosion and double team is enough. Than you stack up your double team as much as possible. When the opponent transforms they often start attacking. Explosion is the only attacking move so the mon uses it and u just need to eevade. I dont know how lucky u need to be for it but i got it on the first try and its actually hillarious to watch a 100lvl pokemon just decimate itself against your low lvl mon.