I'm really not liking the uncomfortable weakness to the standard Choice Band and Dragon Dance Tyranitar. In your threat list, you mention Heatran and Celebi as counters and checks to it, however, I fail to see how they're even remotely safe options. Both are OHKOed by a boosted Tyranitar, and both fail to OHKO back. Gyarados has no business with the Dragon Dancer, and can't switch into the Choice Bander. So basically, you have Metagross and Jirachi as uneasy checks to this behemoth, another concern I have. Why both Metagross AND Jirachi? Who is benefitting from paralysis on this team? Drop Body Slam, go with Stealth Rock on Jirachi, and remove Lead Metagross for something to help with these weaknesses. Right now, Tyranitar, Latias, and even Mamoswine cause serious problems for you. All of which can set up on a good portion of your team, and all of which can either OHKO or 2HKO your team entirely. Call me crazy, but a Weavile might do you more good than you would expect. Let's take a look at a few things, shall we?
A Jolly Weavile has enough Speed to outrun your standard Dragon Dancing Tyranitar and OHKO it with Brick Break if you run Life Orb. It can also utilize Night Slash to screw up Latias who stay in to try and take a Pursuit. Ice Shard will revenge all kinds of Salamence bar Yache Berry versions (extremely rare, and with Stealth Rock and some residual damage, even Yache Berry won't be able to save it. Ice Shard / Brick Break / Night Slash is a given, but the last slot is up to you. You can either run Swords Dance, which will give Weavile awesome offensive stats of 881 Attack with a 383 Speed stat. A +2 Ice Shard even does enough damage to do 58% to a max HP / max Defense Hippowdon, pretty cool if you ask me. You can, however, run Pursuit to remove things such as Gengar and Latias which can stop your Gyarados sweep and threaten to wall Heatran. Up to you really.
If you do take my changes, you can lead with either Rotom-H or Jirachi. Both work fine.
