Umbreon
Blaziken
Charizard
Blastoise
Porygon2
Mewtwo
Hmm...let's see...firstly, why would you have two fire types? Get rid of Charizard. Blastoise is a good tank, no complaints there, and so is Umbreon...that is, if you want two tanks. Porygon2 is a good sweeper. Get rid of Mewtwo though. If you want to actually compete with your team, it's just lame. Granted, Mewtwo isn't unbeatable but you'd be a lot more respected if you used something that's not so much stronger than the average Pokemon.
That leaves you with:
Umbreon
Blaziken
Blastoise
Porygon2
I'd recommend adding in either electric, psychic, grass, or rock/ground types, and physical sweepers.