Hey
I'm not sure how it's been affecting you, but you have a pretty gaping dd tar weakness being able to ohko 4/6 of your team and the other 2 are swiftly 2hkoed so they cannot switch in. It also outspeeds your entire team minus jolteon and kills your main wall in cresselia quite handily. CB tar can also cause you headaches because it can predict you switches and pound you accordingly. To remedy this issue, I would put a swampert over your lead tran.
Swampert@leftovers
252 hp 252 def 4 sp. def
Relaxed/Impish
Waterfall
Earthquake
Stealth Rock
Ice beam/Avalanche
I went with the max hp/def build because when dueling with tyranitar, swampert needs all the hp/def it can get because boosted crunches still hurt quite a bit despite being one of the best tyranitar counters out there.
Next, I would change up your jirachi set a bit. Jirachi just cries when it is left without its main form of reliable stab in psychic. It also wants thunderbolt, which can deal nice neutural damage along with psychic. If hidden power ground has been working for you, but it along with psychic, because hp. ground hits most of the threats that flash cannon does anyway. Psychic is a better stab for jirachi than flash cannon and allows for more coverage, even though psychics coverage sucks as well.
You scizor wants pursuit over night slash as well, because with technician, they are almost the same bp anyways. Also, pursuit packs the obvious advantage of being able to trap ghosts and revenge trap weakend pokes. Pursuit is just all around better on scizor because it snags that technician boost as well as getting the trapping effect that night slash only wishes it could have.
Also, with jolteon, why does it need hp ice and signal beam over hp grass and shadow ball? Raikoulover's topic on choice users states that a choice user should be focusing more on his neutural coverage rather than packing moves solely to hit a few pokes for super effective damage. This is because once you use the move you are locked in to it and a wrong prediction could leave you as easy set up fodder. Thunderbolt already puts a hurt on anything besides grassers that hp ice would hit, namely dragons because they get hit with a stab neutural thunderbolt for the 2hko anyway. Hp grass also offers ground coverage as well. Shadow ball is a better all around move than signal beam as well offering better neutural coverage and still hiting celebi super effectively. Since you now have swampert anyway, tyranitar is less of an issue and you can afford to lose some coverage on him to have all around better neutural coverage.
For cresselia, you might want to consider a resttalking set as that set is not effective when sand or hail is present. This set would do the same thing minus reflect:
Cresselia@Leftovers
252 hp 200 def 56 sp. def
Bold
Rest
Sleep Talk
Ice beam
Thunderwave
This set can also help to wall infernape a bit better because with some special defense investment cresselia can better take an ape fire blast/flamethrower and live to paralyze him and rest off the damage. This cresselia will also boast serious amounts of surviveability and will stick around much longer than your current build.
Tl;dr:
1.Swampert over heatran for better tyranitar countering
2.Change jolteons set up a bit (hp grass over ice and shadow ball over s-beam)
3.Jirachi to either t-bolt and psychic or hp ground and psychic
4.Cresselia to restalker
Hope I helped and good luck.
-chaos 9