I'm rather an amateur myself, but here are my two credits:

Azumarill has the ability Huge Power, which makes its rather unimpressive Attack stat suddenly quite high. It also comes with some great physical moves. You can give it a Choice Band or Life Orb for even more power, an Assault Vest for bulky offense, or a Sitrus Berry to go with a Belly Drum setup. Common moves on Azumarill are Belly Drum (to maximize Attack at the cost of HP), Aqua Jet (for a priority STAB that hits like a truck after Belly Drum; pretty much required since Azumarill is easy to outspeed), Waterfall (stronger Water STAB without priority), Play Rough (Fairy STAB), Superpower (for coverage), and Knock Off (great for crippling opposing pokes that rely on their items, like Choice items or Leftovers).

For any of those, investment in Attack is recommended. I also like to invest in HP, especially if you run Assault Vest.

Belly Drum Azumarill is great for sweeping later in the game, after anything that threatens Azumarill has been dealt with. Choice Band or Life Orb Azumarill has more immediate power that doesn't cost a ton of health, so they're safer for switching in and out. Assault Vest Azumarill is the bulkiest of the bunch, but also the weakest attacker, so it's a good bit more balanced.

As for the rest of your team, you now have two Fairy-types, and all of your current pokes are physical attackers. Steel-types are going to threaten your team, so I'd add a Fire-type to deal with them. Chandelure, Volcarona, and specially offensive Infernape come to mind.

You could go several directions after that, but keep in mind that entry hazards are very important. You'll want something that can set entry hazards and something that can remove them from your side of the field. There are a lot of options for both, fortunately. Tentacruel, Excadrill, Forretress, Starmie, and Cloyster all learn Rapid Spin (which I recommend over Defog for offense); and Chesnaught, Ferrothorn, Greninja, Skarmory, Roserade, and Froslass all learn Spikes (which I recommend over Stealth Rock for this team because of Stealth Rock's reliance on its typing).

Hope I helped. Let me know what you think!

Thanks, this was really helpful, however Mawile is only weak to fire and ground, and not steel? do you still recomend me having a fire type on my team (which may be risky due to the popularity of earthquake) or do you think having fire punch on Dragonite will be enough? I was also thinking about using Roserade for Spikes, I think ill make a spread and moveset for Roserade when I can and post it here, then you can tell me what you think

What I meant by Steel-types giving you trouble is that, between Dragonite, Azumarill, and Mawile, you're pretty likely to be walled. Every one of their STABS would be resisted by Steel-types.

Dragonite's Fire Punch and Azumarill's Superpower would be helpful for coverage, but most Steel-types have really good Def. That's why I think you'd have an easier time with something specially offensive to help deal with them. Earthquake is popular, true, but you thankfully have Dragonite. If you think your opponent is going to use Earthquake, switch out to Dragonite and the move will do nothing. You might even be able to force them to switch out (if they have a Choice Band or their poke is scared of Dragonite) and get a free Dragon Dance. And if you're really worried about Earthquake, Volcarona's only hit neutrally by it (though it IS kinda frail, physically).

I think Roserade would fit into your team nicely. Good choice! (Plus, I like seeing Fire-Water-Grass trios in teams.)

Thanks! I'll consider some Special Attacking Fire types.

Here is what I got for Roserade:

Roserade:
Nature: (Im not sure if I should use a defensive build, or make it faster)
Item: Wide Lens
Ability: Natural Cure or Technician (Not sure how well Poison Point works)
Ev Spread: (Im not sure if I should use a defensive build, or make it faster)
-Sleep Powder
- Giga Drain/Mega Drain (Depending on the ability)
- Sludge Bomb
- Spikes

What do you think? Wide Lens Boosts accuracy of Sleep Powder by 10% from 75% - 85%

I was considering Rotom-Heat for my fire special attacker, but I feel its over shadowed by its washing machine form...Thoughts?

Roserade's physically kind of frail, but it's got a good Special Defense stat and good typing. For defensive Roserade, I'd use Black Sludge for the item and Natural Cure as the ability. A typical EV spread for defensive Roserade is 240 HP / 252 SpD / 16 Spe.

Offensive Roserade wants a Timid nature and full investment in SpA and Spe. If you want Hidden Power, Technician will boost it; otherwise, go with Natural Cure. Even after a Technician boost, Mega Drain is not as powerful as Giga Drain. Typically, you'd see a Life Orb on this Roserade.

Your moveset will work with either version. Wide Lens will take Sleep Powder's shaky accuracy and make it, well, slightly less shaky. It's generally not as useful as passive recovery or extra damage output.

As for whether to pick offensive or defensive Roserade, it depends on the rest of your team. Specifically, do you want a balanced team or an offensive team? Right now, it looks like you're leaning toward an offensive team.

Rotom-Heat sounds like it could work, but there are two things about it that worry me: its only Fire-type STAB is Overheat, which reduces its SpA once used; and it's weak to Stealth Rock. Basically, you'll have to switch it in and out a lot to make it work, and switching without removing hazards will kill it fast. But Overheat makes for a great hit-and-run attack, and if you can keep those hazards off the field, I think you'll like Rotom-Heat.

Most of the time, Rotom-Wash or Heatran would be preferred over Rotom-Heat, but you're looking for a Fire-type, and Earthquake will destroy Heatran if it's not holding an Air Balloon. But Heatran has better stats overall and is much more versatile. If you don't mind having two Steel-types on your team, give Heatran a try. It has Fire immunity, so if it's still holding an Air Balloon, it can switch into any Fire- or Ground-type attacks aimed at Mawile.

You can't do 6v6 in Battle Spot

I recommend first deciding what kind of team you want.
For example, I run heavy offensive\speed teams.
Figure out what your win conditions are and build upon that.
Every good team is based on trial and error. You have to see what works for you.
Also a pokemon battle is not only based on the team but the person using the team. If you know your team well enough you can cope better with different battle senerios.
Knowledge is power in the world of pokemon battling. Quite literally.