Jirachi can already run a parafusion set with Thunder/Water Pulse/CM(or Wish)/Sub. You're already abusing THunder on Molota, so you need rain. Plus, using an 8 pp attack in a mono-attacking set is not good unless you are boosting, Arceus, or have no immunities. Ground types completely Wall you, and frankly, Jirachi just does it better imo. Better typing, bulkier, and can set-up easier.
thats not the only set it could run though. it could always run, like i said before, an aria forme set, teeter dance/thunder/psyshock/cc(focus blast) with bulk. lefties, and max hp/max SpD, play around with the evs and let it outspeed standard SpD rachi. haxing the haxer.