Hello, this is Shounak from Netbattle.
My Team:

Metagross @ Leftovers ** Wise Steel X
Trait: Clear Body
EVs: 252 Atk / 184 Spd / 72 SAtk
Naughty Nature (+Atk, -SDef)
- Earthquake
- Explosion
- Hidden Power [Grass]
- Meteor Mash

Tyranitar (M) @ Choice Band ** Hollow Rockmass
Trait: Sand Stream
EVs: 4 HP / 252 Atk / 252 Spd
Adamant Nature (+Atk, -SAtk)
- Earthquake
- Focus Punch
- Hidden Power [Bug]
- Rock Slide

Magneton @ Leftovers ** Thunder Trio
Trait: Magnet Pull
EVs: 176 HP / 8 Spd / 172 SAtk / 152 SDef
Modest Nature (+SAtk, -Atk)
- Hidden Power [Fire]
- Rest
- Sleep Talk
- Thunderbolt

Vaporeon (M) @ Leftovers ** Vapor Finfish
Trait: Water Absorb
EVs: 252 HP / 184 Def / 72 SAtk
Bold Nature (+Def, -Atk)
- Ice Beam
- Roar
- Surf
- Wish

Gyarados (M) @ Leftovers ** Scarlet Fangs
Trait: Intimidate
EVs: 4 HP / 252 Atk / 44 Def / 208 Spd
Adamant Nature (+Atk, -SAtk)
- Double-Edge
- Dragon Dance
- Earthquake
- Hidden Power [Flying]

Swampert (M) @ Leftovers ** Super Shounak
Trait: Torrent
EVs: 176 HP / 228 Def / 104 SAtk
Relaxed Nature (+Def, -Spd)
- Earthquake
- Hydro Pump
- Ice Beam
- Protect

Note any improvements in Movesets, Items, EV's and even Pokemon.

Main concerns:
Ground weakness
No special wall

To fix that you could

Snorlax (Curselax) > Tyranitar
Zapdos > Swampert (for special purposes and gyarados counter)
Resstalk set on metagross. You have enough things to switch in Swampert so no need for HP grass.