Set: Mixed Jirachi

Jirachi @ Leftovers
Trait: Serene Grace
EVs: 108 HP / 148 Atk / 100 SAtk / 56 SDef / 96 Spd
Lonely Nature (+Atk, -Def)
- Iron Head
- Fire Punch
- Thunder Wave
- Hidden Power [Ice]

Another Jirachi set, but this one plays completely differently. One of the best ideas to come out of the franky / ojama collaboration was this Mixed Jirachi set, which functions as both a defensive check and an offensive lure to key threats. The giant surprise factor of this Jirachi can net some nice kills on crucial opponents.

One thing that probably sticks out is the complicated EV spread. It allows Jirachi to outpace Adamant variants of Dragonite and Mamoswine, avoid being 2HKOed by Specs Latios' Surf and KO Gliscor after a small bit of prior damage. The extra Attack investment helps to make Jirachi a fairly powerful physical attacker by giving Iron Head and Fire Punch higher damage.

Besides covering special attackers like Latios, Latias and Reuniclus, Mixed Jirachi can also lure out some important opposing team members. Fire Punch is a 2HKO at the very least on Ferrothorn and Scizor, sometimes OHKOing the latter after Stealth Rock. HP Ice scores a very unexpected KO on Gliscor, opening up opportunities for physical attackers to sweep. Thunder Wave works well with Iron Head to give opponents only a 30% chance to move. 

As mentioned earlier, physical sweepers pair well with this set. Excadrill is one of the best team members, as it can sweep teams after Gliscor has been taken out and can even abuse Rock Slide's flinch rate to get past a paralyzed Skarmory. I've personally been using Scarf Terrakion as a revenge killer and late-game sweeper with this set, and a lot of teams crumble to it once Gliscor is out of the picture. Due to the sheer popularity of the specially defensive set, almost no one will expect the extra coverage moves Mixed Jirachi carries.