I am confused. The set doesn't take the advantages of Goodra. Try out a more offensive Goodra:
Goodra @ Assault Vest:
Trait: Hydration / Gooey
EVs: 252 HP / 252 Sp.Atk / 4 Sp.Def
- Dragon Pulse
- Fire Blast
- Ice Beam
- Focus Blast
Defensive calcs shows that Mega-Mewtwo Y will have to 4HKO Goodra with Ice Beam while running this set. Not as offensive, but in fact, Goodra's true strenght is in its defensive stats. Still, the set can work gorgeously well as it has so much diverse coverage. The sole and only Pokémon who will totally wreck this set as well as Goodra is...
Azumarill. That's why you will need a solid counter.
Again, unless you run Scizorite, there are truly no reasons not to chose Adamant Choice Band, so here we go:
Scizor @ Choice Band:
EVs: 252 Atk / 252 HP / 4 Sp.Def
- Bullet Punch
- Bug Bite
- Pursuit / U-Turn
- Superpower / U-Turn
It will have to go, because another mega will be needed. Replace it with Gliscor.
Gliscor @ Toxic Orb:
Trait: Poison Heal
EVs: 252 HP / 252 Def / 4 Atk
- Stealth Rock
- Swords Dance
Not to use against flying.
The Bulk Up set is not as strong as its other sets. Go for:
Talonflame @ Liechi Berry / Salac Berry / Sharp Beak / Sky Plate:
Trait: Gale Wings
EVs: 252 Atk / 208 Speed / 48 HP
- Flare Blitz
- Brave Bird
- Swords Dance
- Natural Gift / Roost
Item variety. If you run Natural Gift which now has a nice 80 BP, then Liechi Berry will make it Grass to attack Rotom-W, your counter, and Salac Berry will counter Heatran and Tyranitar with the Fighting typing.
As for the two other items, they are basically the same, but I list them both if needed. You will not run Berries without Natural Gift. Roost is to run without Berries. Capiche ?
Ah, and this is le Wallbreaker Set de Talonflame.
Why ? Your team is nowhere close to be a Sandstorm team. Remeber the counter to Azumarill which is needed ? It will replace Tyranitar.
Venusaur @ Venusaurite:
Trait: Thick Fat
EVs: 252 HP / 252 Sp.Atk/ 4 Sp.Def
- Giga Drain
- Sludge Bomb
- Hidden Power Fire
Its presence is very random and useless. Florges will be better for your team:
Florges @ Leftovers:
Trait: Flower Veil
EVs: 252 HP / 252 Sp.Def / 4 Sp.Atk
Support +Toxic Stall.
Good Luck :D