Oh yeah i remembered another Pokemon that counters the four most popular Jirachi sets (SubCM, SpD, Scarf that lack Fire Punch, which is most of them, and Wish + CM):
Specially Defensive Scizor! The good old Scizor has no problem countering the versatile pixie, as long as it holds Lefties to avoid dying from flinchax. You don't believe me? Here are some calcs:
- Thunder vs Scizor: 18.89 - 22.38%, possible 6HKO
- +1 Thunder vs Scizor: 28.19 - 33.43%, possible 4HKO
- Iron Head from SpD Jirachi: 12.5 - 14.82%, 9HKO at best
- Iron Head from Scarf Jirachi: 15.69 - 18.89%, possible 8HKO
- +2 Bug Bite vs 252 HP / 236+ Jirachi: 49.75 - 58.66%, 68.36% chance to 2HKO
- +2 Bug Bite vs 252 HP Jirachi: 68.31 - 80.44%
- +2 Bug Bite vs 4 HP Jirachi: 80.93 - 95.3%
- +2 Bullet Punch vs 252 HP / 236 Def+ Jirachi: 16.58 - 19.55%
- +2 Bullet Punch vs 252 HP Jirachi: 22.77 - 26.73%
- +2 Bullet Punch vs 4 HP Jirachi: 26.97 - 31.67%
Full-proof counter pretty much. Just pick some partners to beat the stuff that wall Scizor and you are good to go!