Anyone want to rate my team?

Right, so I'm getting back into Pokemon after not playing for a while and this is the team I decided to use:


Hippowdon

Nature: Careful
Ability: Sand Force
Movelist: Fire Fang, Thunder Fang, Revenge, Earthquake

Jolteon

Nature: Lax
Ability: Volt Absorb
Movelist: Thunderbolt, Shadow Ball, Pin Missile, Double Kick

Arcanine

Nature: Jolly
Ability: Flash fire
Movelist: Close Combat, Iron Tail, Wild Charge, Flamethrower

Snorlax

Nature: Impish
Ability: Thick Fat
Movelist: Rest, Rollout, Sleep Talk, Brick Break

Blastoise

Nature: Any of the ones that have no effect.
Ability: Torrent
Movelist: Ice Beam, Dark Pulse, Surf, Brick Break

Vileplume

Nature: Modest
Ability: Effect Spore
Movelist: Giga Drain, Venoshock, Stun Spore, Energy Ball


So, is it any good? Anyone got any suggestions to improve it?

Well, I don't know how far in-game you are, but this team seems to have good coverage for most of the Gyms (wherever you may be) and the Elite Four, as well. But since you have Ice Beam i'm going to guess that you're already nearing the Elite Four. Jolteon can slam Siebold, Blastoise and Hippowdon are well effective for Malva, and so on and so forth. I don't really have anything else to add.

I've actually finished the game, I'm probably going to train this team on my Y cart then use it to battle online and in the Battle Maison.

Alright, let's see what I can do.

Jolteon
Thunderbolt is a good STAB for it.
Shadow Ball is a good way of doing some decent damage to that pesky Gardevoir.
Double Kick and Pin Missil are pretty bad moves, especially on a special attacker like Jolteon. If you have access to ORAS tutors, you might want to consider Shadow Ball and Signal beam as alternatives. Even T-Wave could be more useful. Jolteon is going to be fragile regardless of nature, If you can I'd suggest switching to Modest if you go with my other suggestions.

Vileplume
If you are going to run Venoshock, replace Stun Spore with Toxic of at least Poison Powder. It also doesn't need two grass STAB moves. Try this

Vileplume @Poison Barb
Modest/Calm
-Toxic
-Venoshock
-Energy Ball/Giga Drain/Petal Blizzard
-Moon Blast/Dazzling Gleam

Other than that I think you're good to go