Jirachi's purpose:

Well, what do you know? Aren't you so damn cool, using a Specially Defensive Rachi in the rain, huh? Well, weakened Fire attacks definitely helps. Max HP variant to get some very decent 202 wishes across to my teammates. Not only that, but he serves pretty well as a paralysis spreader, which is gladly appreciated by BandRaptor, who could use all the speed he needs, and Thunderus-T, who cant outspeed other things such as Latios or Terrakion. While he really doesn't sppreciate it, Rachi is mainly my go to guy (or girl, idk it's gender >.>) when i need something to take a Will-O-Wisp or a Scald. Being able to outstall a SubCM Lati@s (if i can land in a Body Slam Parahax), taking only 44%-49%ish damage from a +3 Dragon Pulse the Eon duo has to offer is pretty impresive. And don't forget how fun it is to ParaFlinch someone to death :3