Cloyster
Ahhh, great set. Nothing to do here.
Instead of Espeon, I recommend Claydol. It can fill the role as spinner, Psychic Type, and Steel counter(thanks to Ground typing). I would use:
Claydol
@ Leftovers
252 Def, 152 SpeDef, 4 HP, 100 SpeAttack
Earth Power
Psychic
Rapid Spin
HP Grass
So, yeah.. I can understand that Espeon gives team support, so the set I gave is only for consideration.
Dragonite
Ahh, perfect set. wouldn't change anything. (see above pic)
Volcarona
Hmm. Well, those EVs in Defense aren't doing a whole lot for Volca, but it's your choice... I don't have much to add at the moment, I might edit this part.
Metagross
OMG, this is my set! Obviously, I wouldn't change much, since this is what I'm using. If it isn't quite working for ya, use Lefties and get rid of Trick. Replace with Meteor Mash or Stealth Rock. If you're worried about Air Balloon Steels walling your team, use Brick Break.
Gengar
Hmm. Good set, but I have a few suggestions. One is working Pain Split into there. That will annoy Steel Types, with generally have more HP than Gengar, and will ruin Sturdy.
The second suggestion is giving him 0 IVs in HP to strengthen Pain Split.
EDIT: Might want to consider Focus Sash..
Well, good team SP! I remember battling this. I know my rating kinda stunk, but I did my best. GL!