>>20430221Disclaimer: not going to be pretty. Imagine me snapping my fingers a lot and saying oooh girl in a condescending way.
First of all, Seismic Toss and Toxic/Twave > everything else Blissey can run for offensive presence. Counter seems great up until you get OHKO'd by a Heracross or Mienshao, or when you're stuck in a stall war.
Two bans on the same team is a no-no, at least in my opinion. Either drop Victini or slap a scarf on it or Hydreigon. I also prefer Heracross's Guts Sleep Talk set, but you have Blissey who can switch into Sleep moves and switch out with Natural Cure. Because you're using Natural Cure instead of fucking Serene Grace. Heracross also needs speed investment or else it's dead weight.
If you do choose to keep Banded Victini, drop Quick Attack for Trick to shut down walls.
Hydreigon is all wrong. LO 3 attacks runs Roost, not Roar. Hydreigon isn't bulky enough to pull off Roar, and HP Grass is absolutely worthless. Flamethrower too. Dark Pulse/Draco/Fire Blast or U-turn.
Aerodactyl is messed up too. Don't be a pussy, use Stone Edge. Aerial Ace is also a great STAB that makes use of its ability. use a third slot for a coverage move, and Iron Head is not a coverage move. Slap Taunt or Rocks on the fourth slot to make it either an anti-lead or a general lead. Crunch is decent as a third attack, but your team composition should be considered when slotting that last attack in, and your team is far from being finished.
Sixth team slot should be a spinner/defogger. Maybe even a physical wall that can remove hazards. I particularly like Gligar for this, but Empoleon works too.
But seriously, reassess your team. Here's the most recent 1630 usage stats for ideas:
http://sim.smogon.com:8080/Stats/2014-07/moveset/uu-1630.0.txt 
