XY OU Celebi and Mega Mawile Team :]

[etw44]

This is my team with the ridiculously powered Mega Mawile and the neglected Celebi.

Mawile @ Mawilite
Ability: Intimidate
EVs: 160 HP / 252 Atk / 96 Spe
Adamant Nature
- Substitute
- Focus Punch
- Play Rough
- Sucker Punch

This set uses the combination of the powerful Focus Punch and the safety properties of Substitute to create a deadly walbreaker. The speed Evs are to outspeed min invested Tyranitar. Attack is maxed for godly power. The rest of the Evs are dumped into Hp for added bulk.

Landorus-Therian (M) @ Leftovers
Ability: Intimidate
EVs: 252 HP / 168 Def / 88 Spe
Impish Nature
- Stealth Rock
- Earthquake
- U-turn
- Stone Edge
This set uses Landorus-T's Intidimate ability, natural power, and decent speed to great effect. 88 speed EVs are to outspeed neutral max invested base 70s, such as Bisharp. HP is maxed out as is defense to add much appreciated bulk to Landorus-T for it to act as a bulky pivot.

Latias (F) @ Life Orb
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Draco Meteor
- Psyshock
- Healing Wish
- Defog
This set utilites Latios's movepool, bulk, and power to have a offensive supporter. Max speed is used to tie with other base 110s, such as Latios, opposing Latias, and Gengar. Max Special attack gives it the power to do a lot damage with its STAB moves.

Tyranitar @ Choice Scarf
Ability: Sand Stream
EVs: 172 Atk / 88 SpA / 248 Spe
Naive Nature
- Stone Edge
- Crunch
- Pursuit
- Fire Blast
This set utilizes Tyranitar's movepool, power, and bulk to surprise and kill many of its checks and counters such as Ferrothorn while also becoming a great revenge killer. Speed evs are to outspeed maximum invested base 115s, such as Starmie. 172 Attack Evs are to OHKO 40 HP Gyarados after Stealth Rock at -1. Rest of Evs are thrown into Special Attack to be able to have a chance to OHKO purely Physically Defensive Ferrothorn.

Azumarill @ Assault Vest
Ability: Huge Power
EVs: 252 Atk / 28 Def / 228 Spe
Adamant Nature
- Superpower
- Aqua Jet
- Waterfall
- Play Rough
Ths set combines Azumarill's power and bulk to make an amazing tank. Speed Evs are to outspeed 8 speed Heatran and hit it with a powerfall Waterfall. Attack is maxed out to achieve max damage to murder your foes. Rest are thrown into Defense for added bulk.

Celebi @ Leftovers
Ability: Natural Cure
EVs: 252 HP / 180 Def / 56 SpD / 20 Spe
Bold Nature
- Recover
- Thunder Wave
- Giga Drain
- Hidden Power [Fighting]
Celebi bulk tho? Hp is maxed out for supreme bulk. 180 Defence is to live a +3 Mega Gyarados's Ice Fang. 20 Speed to outspeed neutral base 70s, such as Bisharp. Rest is thrown into Special Defence for good mixed bulk. Hidden Power Fighting is to catch Bisharp on the switch and OHKO.
Please tell me if there are any flaws or mistakes nicely. please and thank you! #aim

 

[Kacey Nu]

(Because Mawile doesn't have its Steel STAB) the team looks like it can't fight physically defensive Fairies that use and pass Wish causing your team to have the HP deficit each round.
I'm guessing that you say Mawile's power is ridiculously high because of how it plays for you - the mere presence of Mawile scares the opposing Fairy away while you wreck whatever comes in with a Substitute, right? It's a great set too imo, but I say Wish Passing from a skilled player overcomes such a thing. Hope you'll find what works best here.

The above point notwithstanding, you can remove Healing Wish for Wish on Latias to pass your own stuff around. I recommend it because your team is not that offensive and can use more than one heal. Healing Azumarill so it always threatens Faires, or Mawile without losing a Pokemon sounds good to me.