Please help me with my Ubers team

So I finally got around to getting back into battling on Pokemon Showdown again after not being on it for something like 6 months. I had to scrap most of my teams. I've made a team for Ubers, but I'm not sure if it'd work. I sorta just threw some stuff together (team synergy is still something I have yet to truly grasp). So you all think you could help me out?


-Zekrom w/Life Orb
Nature: Lonely
Ability: Teravolt
EVs: 104 HP, 148 Attack, 252 Sp.Attack, 4 Speed
Moves: Bolt Strike, Dragon Claw, Draco Meteor, Flash Cannon

-(Mega) Mewtwo w/Mewtwonite Y
Nature: Timid
Ability: Insomnia
EVs: 252 Sp.Attack, 252 Speed, 4 Defense
Moves: Psystrike, Aura Sphere, Ice Beam, Calm Mind


-Dialga w/Leftovers
Nature: Modest
Ability: Pressure
EVs: 252 HP, 200 Sp.Defense, 56 Sp.Attack
Moves: Stealth Rock, Dragon Pulse, Flash Cannon, Roar


-Ho-oh w/Leftovers
Nature: Adamant
Ability: Regenerator
EVs: 248 HP, 176 Attack, 84 Sp.Defense
Moves: Sacred Fire, Roost, Brave Bird, Substitute


-Arceus w/Lum Berry
Nature: Adamant
Ability: Multitype
EVs: 252 Attack, 252 Speed, 4 HP
Moves: Extreme Speed, Swords Dance, Recover, Shadow Claw


-Xerneas w/Life Orb
Nature: Naughty
Ability: Fairy Aura
EVs: 244 HP, 252 Attack, 4 Sp.Attack, 8 Speed
Moves: Moon Blast, Horn Leech, Close Combat, Night Slash

Now, you're probably thinking "WTF is with that Xerneas set?". It's something I wanted to try out. Xerneas has a good physical movepool and base 131 Attack, and I'd like to see if it'd work. Sure, the thing runs special sets, but that's another reason why I wanna try it: surprise factor. So the Xerneas stays, but if you have any suggestions to make it better, tell me.

As for the rest of the team, any and all critiques are welcome (including swapping a Pokemon for something else). It's a new metagame in Gen 6, so I'm not sure what still works an what doesn't.

Specially-based Xerneas is your best bet, even though it has a lot of physically-based coverage options. It lacks Play Rough, so a primarily physically-based set is out of the question:
-Geomancy
-Moonblast
-Hidden Power (Fire)/Focus Blast
-Substitute
Nature: Modest
EVs: 192 HP/252 Atk/64 Spe
Item: Power Herb

or
-Moonblast
-Close Combat
-Hidden Power (Fire)
-Thunderbolt/Calm Mind
Nature: Naive
EVs: 4 Atk/252 SAtk/252 Spe
Item: Life Orb

or
-Moonblast
-Close Combat
-Thunderbolt
-Megahorn
Nature: Naive
EVs: 76 Atk/180 SAtk/252 Spe
Item: Choice Scarf

Xerneas with power herb is so ridiculous. Unless you can kill it with priority it will sweep most everything once it uses geomancy.

Ok, so I'll go with a mixed Xerneas instead. Geomancy Xerneas I'll put on another Ubers team.


Any other suggestions?