Need help improving my team

[Pastatoast]

Hey, I tried to make a team based around using Mawile (especially mega-mawile), and I wanted to see what you guys' opinions were. I was also thinking about making a team based around Haxorus, so if you want to leave a suggestion below, feel free to do so.

TEAM

Mawile
Item: Mawilite
Nature: Adamant
EVs: 252 HP / 252 Atk / 4 SpD
Moves: Sucker Punch / Play Rough / Iron Head / Swords Dance
Ability: Intimidate

Gliscor
Item: Toxic Orb
Nature: Adamant
EVs: 252 Atk / 4 HP / 252 Spe
Moves: Aerial Ace / Earthquake / Swords Dance / Agility

Excadrill
Item: Leftovers/Shell bell
Naure: Adamant
EVs: 252 Atk / 4 HP / 252 Spe
Moves: Earthquake / Rapid Spin / Rock Slide / Swords Dance

Skarmory
Item: Flying Gem
Nature: Impish
EVs: 252 HP / 232 Def / 24 Spe
Moves: Spikes / Stealth Rock / Whirlwind / Brave Bird
Ability: Keen Eye

Rotom-Wash
Item: Leftovers
Nature: Calm
EVs: 252 HP / 4 SpA / 252 SpD
Moves: Thunderbolt / Volt Switch / Hydro Pump / Will-o-Wisp
Ability: Levitate

Heatran
Item: Choice Specs
Nature: Modest
EVs: 252 SpA / 252 HP / 4 SpD
Ability: Flash Fire
Moves: Heat Wave / Eruption / Earth Power / Fire Blast

---------------------------

Ok, so that was my team. I was also thinking of putting a scolipede as a baton passer, but I imagined he'd be somewhat weak in comparison to other alternatives. Any feedback helps- Thanks!

 

[PlatinumDude]

Is this a Poke Bank team? Heatran isn't available yet till that point.

Mawile needs enough Speed to outspeed uninvested Aegislash, Scizor and Azumarill (132 HP/252 Atk/124 Spe). Even though Fire Fang is needed to hit other Steels, Iron Head still deserves a mention for serving as a Steel STAB.

Gliscor is usually seen using defensive sets, not offensive ones. Its Swords Dance set has taken a huge hit with the unavailability of Flying Gem:
-Earthquake
-Toxic
-Substitute/Taunt
-Protect/Roost
Nature: Impish
EVs: 244 HP/252 Atk/12 Spe
Item: Toxic Orb
Ability: Poison Heal

or
-Earthquake
-U-turn
-Taunt
-Roost/Knock Off
Nature: Impish
EVs: 244 HP/48 Def/216 Spe
Item: Toxic Orb
Ability: Poison Heal

or
-Substitute
-Baton Pass
-Earthquake
-Taunt/Swords Dance/Agility/Rock Polish
Nature: Impish
EVs: 244 HP/48 Def/216 Spe
Item: Toxic Orb
Ability: Poison Heal

If you want a double dancer that doesn't rely on Gems, make do with Diggersby:
-Agility
-Return
-Earthquake
-Wild Charge/U-turn/Stone Edge/Swords Dance
Nature: Adamant
EVs: 252 Atk/4 Def/252 Spe
Item: Life Orb
Ability: Huge Power

Excadrill's item should be Life Orb or Air Balloon. Shell Bell is such an inferior item. Outside of sandstorm, its ability should be Mold Breaker.

Sturdy is the superior ability for Skarmory, due to the fact that it can't be KOed in one hit at full health. Stealth Rock isn't available for it till Poke Bank. Flying Gem isn't available at all, even with Poke Bank released:
-Spikes
-Whirlwind
-Roost
-Brave Bird/Taunt
Nature: Impish/Careful
EVs: 244 HP/252 Def/32 SDef or 244 HP/32 Def/252 SDef
Item: Leftovers/Shed Shell
Ability: Sturdy

Wash Rotom now is better off using a physically defensive spread to check/counter Talonflame better:
-Volt Switch
-Hydro Pump
-Will-o-Wisp
-Rest
Nature: Bold
EVs: 252 HP/252 Def/4 SDef
Item: Chesto Berry

or
-Discharge
-Volt Switch
-Hydro Pump
-Hidden Power (Ice)
Nature: Modest
EVs: 232 HP/56 SAtk/220 Spe
Item: Assault Vest

or
-Volt Switch
-Hydro Pump
-Hidden Power (Ice)
-Trick/Thunderbolt
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Choice Specs/Choice Scarf

Heatran isn't available till Poke Bank, either. I suggest you find something else to replace it if this isn't a Poke Bank team. I can't think of any specifics at the moment.

Edit: to add to Zekrom's suggestion, Eruption Heatran only have Quiet natures, as the Pokemon Ranger event set it that way.

 

[Nah]

Like Platinum said, Wash Rotom is better using a physically defensive set. If you really wanna use an offensive set, this'd work better than what you got now:

-Rotom-W w/Leftovers or Sitrus Berry
Nature: Modest
Ability: Levitate
EVs: 232 HP, 56 Sp.Attack, 220 Speed
Moves: Volt Switch/Thunderbolt, Hydro Pump, Will-o-wisp, Hidden Power

If this is a PokeBank team, consider this as well:

Skarmory doesn't need both Spikes and Stealth Rock, especially since it likes to have Roost. So switch one with that. Heatran also doesn't need 3 fire attacks. No Pokemon does. It just needs one fire attack: either Lava Plume or Fire Blast will do. It's other moves should be: Earth Power, Dragon Pulse, and Flash Cannon.

If this is not a PokeBank team:

Tyranitar or Hippowdon should be your Heatran replacement. Skarmory, Excadrill, Gliscor, and Mega Mawile aren't negatively effected by its sandstorm, and Rotom (if going the defensive route) doesn't care much about the sandstorm. If running Tyranitar/Hippowdon, Excadrill should have Sand Rush as its ability; an Excadrill in the sand with Sand Rush can be beastly.

Finally, I wouldn't recommend basing a team around Haxorus. Like Hydreigon, it took a nasty hit from the introduction of Fairies. The idea behind Haxorus is almost always SD/DD/Choice Band, then spam Outrage. Which no longer works with Fairies skipping about.
Scolipede isn't a bad Baton passer (it's arguably better than Ninjask). But I think Tyranitar/Hippowdon works better for your team with all its sand-friendly Pokemon.

 

[Pastatoast]

Ok, thank you guys for the great constructive criticism- it's really going to help me think around some flaws on most of my teams. ( Also, Tyranitar Excadrill is sounding pretty good, right now)

 

[champagnepapi]

a very big weakness to this team is mega lucario with ice punch/close combat/sd/filler, it can pretty much outspeed and ohko everything at +2, and nearly does so without any boosts at all. terrakion is a really big threat as well for this reason, gliscor has no defense investment so it's likely ko'd by stone edge after terrakion gets a swords dance.

skarmory is a really shaky check to both of these pokemon since it's got a very low hp stat desptie its high defense. to be honest i'd put your own choice banded terrakion over excadrill. cb terrakion can help weaken mawile's counters and heatran, the main switchin to mawile, is a good opportunity for cb terrakion to get in and wreak havoc. i'd also run a scarfed landorus t over gliscor to be able to revenge kill strong fighting types, as well as dd dragons and all that. last move is to put defog>spikes on skarmory. defog is far better than rapid spin and skarm should have ample opportunities to get in. besides that, put hp ice over one of heatran's fire moves