Multi Gen Need an Uber team

[xFsGenzxD1]

Want an uber team for competitive

Pokemon I have:

Xerneas
Ability: Fairy Aura
Sassy Nature

Arceus
Ability: Multitypw
Serious Nature

Yveltal
Ability: Dark Aura
Impish Nature

Lugia
Ability: Pressure
Lonely Nature

Darkrai
Ability:Bad Dreams
Gentle Nature

Deoxys
Ability: Pressure
Calm Nature

Celebi (Not sure about this one)
Ability: Natural Cure
Timid Nature

Zekrom
Ability:Teravolt

Mewto (Mewtonite X)
Ability:Pressure
Brave Nature

Mewto
Ability:Pressure
Relaxed Nature
ALL EVS ARE CURRENTLY AT 0
If you could help me pick out items to put on each and give me their movepools that would be great,
also if you think that there are any other ones that could benefit my team, please tell me, it would help a lot

 

[Fireburn]

Check this thread for resources to get started: http://www.smogon.com/forums/threads/rules-general-information-and-helpful-links.3536522/

I will say though that most of your Pokemon barring Yveltal have pretty bad natures. I would encourage soft-resetting for better IVs/nature or hitting up the Wifi forum for better quality legendaries. Check our analyses for an idea of what natures/EVs are good on which Pokemon.

Post things like this in SQSA ("Simple Questions, Simple Answers", each forum has a thread like this) next time. Welcome to Smogon!