My First Uber Team

Ok,this team is my first attempt at creating an uber team.I don't really want to make an all-legendary team but just a team strong enough to take on well trained Ubers...
PS:As usual,my teams are based on Double Battles

1-Giratina(Origin Form)
Griseous Orb (Not sure about the nature)
Shadow Force
Dragon Claw
Aura Sphere
Earth Power

2-Ho-oH
Expert Belt,Serious Nature(The nature I got in my game.I'd wish Adamant myself...)
Sacred Fire
Sky Attack
Sunny Day
Earthquake

3-Palkia
Lustrous Orb,Modest
Spatial Rend
Hydro Pump
AncientPower
Ice Beam

4-Heatran
(Not sure for item),Modest or Quiet
Magma Storm
Heat Wave
Eartquake
Iron Defense

5-Gengar
BrightPowder,Modest,Timid or Hasty
Shadow Ball
Giga Drain
Hypnosis
Will-o-wisp

And I didn't find an ideal last member yet...

Need EV suggestions? I'm pretty bad at 'em, so I'll leave those for Sami. =P

Giratina-O won't be as much of a tank as normal Gira, but looks like you're going for a mixsweeper....two-turn attacks usually don't work very well in Singles but it might be good fro some mindgames in Doubles. I dunno. (I'm not very experienced in Ubers, in case you couldn't tell xD).

I don't think there's a lot of SR in Ubers, but Ho-oh is obviously up a river of excrement in a native american water vessel without any means of propulsion if your opponent does turn out to have it. >_>
I'm still confused as to why you would want a Hasty Gengar....holding Brightpowder o_0