Here's a useful team set I've been using in Ubers:
Dialga @ Leftovers
Ability: Pressure
EVs: 252 Hp(tweak), 192 Attack (tweak), 64 Sp Attack (tweak)
Nature: Brave
- Outrage
- Stone Edge
- Hone Claws
- Fire Blast (tweak)
Mixed Offensive Dialga surprises players usually. It's role is to take on Ho-Oh, Ferrothorn, and Zekrom if possible, as well as other Arceus's other than Fighting and Ground. Overall it's the main sweeper of the team. Mixed Zekrom comes in whenever Dialga is hurt or is down. Since Hone Claws boosts Attack, as well as boost Accuracy. Stone Edge and Fire Blast take advantage of the Accuracy boost and Stone Edge, as well as Outrage, gets stronger. The Hp investment is so Dialga can take more hits, and it has some nice defenses at it's state.
Zekrom @ Life Orb
Ability: Terravolt
EVs: 168 Attack, 172 Sp Attack, 168 Speed,
Nature: Mild
- Bolt Strike
- Dragon Claw
- Draco Meteor
- Thunder
This Zekrom set fills in many roles. It's so I can hit around walls and bait the Groudon switch. Also counter's non scarfed Kyurem W/B with the Speed Ev's. If they have a Kyogre you can turn it against them with Thunder. But Groudon still counters it. It's a back-up Physical/Special Sweeper when any of the team goes down.
Arceus-Dark @ Dread Plate (whole set is tweaked)
Ability: Multitype
EVs: 224 Sp Attack, 224 Speed, 60 Hp
Nature: Modest
- Calm Mind
- Judgement
- Flamethrower
- Recover
My main counter to Lugia. Whenever Arecus-Dark comes in they assume I have Refresh over Flamethrower, so they switch in Ferrothorn not knowing I have Flamethrower and BAM!!! However Blaziken becomes a problem so I have to switch. This mighty Dark Lord will make all Lugia's fear it! Giratina won't stand to defeat it either!
Giratina @ Leftovers
Ability: Pressure
EVs: 200 Defense, 200 Sp Defense, 108 Sp Attack
Nature: Modest
- Calm Mind
- Dragon Pulse
- Rest
- Sleep Talk
It walls many and can set up Calm Minds to fight offensively. Though getting up Sub on Giratina is the problem to this set, Kyurem is the problem as well. Ferrothorn checks it completely. It surprises other Giratina walls by setting up Calm Minds and hitting hard. Mewtwo can be walled, but only done right if Giratina set up a few Calm Minds already.
Mewtwo @ Leftovers
Ability: Pressure
EVs: 128 Sp Attack, 128 Speed, 252 Hp
Nature: Bold
- Calm Mind
- Fire Blast
- Recover
- Psystrike
This Mewtwo blasts Ferrothorn and Forretress with Fire Blast and Psystrike to counter Blissey. Physical attackers gives it problems. The HP investment is so it has some bulk and take hits. Mewtwo is fast as already it is. So a some Speed investment and some Sp Attack investment, with the side of max Hp, makes it pretty bulky.
Forretress @ Leftovers
Ability: Sturdy
EVs: 232 Defense, 232 Sp Defense, 42 Attack
Nature: Careful
- Rapid Spin
- Bug Bite
- Stealth Rocks
- Volt Switch
Just a Rapid Spinner and Stealth Rock user. But it has the other role to break the Sash for Deoxys-A ond other formes. Volt Switch to get the switch initiative. Forretress is the huge wall to Physical Pokes, with Bug Bite along side it can hit Mewtwo hard to put it within Revenge Killer range. And Bug Bite is for predicted Taunt users, which kinda works if Mewtwo has Taunt.
Still under testing, making some of those tweaks. The Ev spread is put accordingly.

Dialga @ Leftovers
Ability: Pressure
EVs: 252 Hp(tweak), 192 Attack (tweak), 64 Sp Attack (tweak)
Nature: Brave
- Outrage
- Stone Edge
- Hone Claws
- Fire Blast (tweak)
Mixed Offensive Dialga surprises players usually. It's role is to take on Ho-Oh, Ferrothorn, and Zekrom if possible, as well as other Arceus's other than Fighting and Ground. Overall it's the main sweeper of the team. Mixed Zekrom comes in whenever Dialga is hurt or is down. Since Hone Claws boosts Attack, as well as boost Accuracy. Stone Edge and Fire Blast take advantage of the Accuracy boost and Stone Edge, as well as Outrage, gets stronger. The Hp investment is so Dialga can take more hits, and it has some nice defenses at it's state.

Zekrom @ Life Orb
Ability: Terravolt
EVs: 168 Attack, 172 Sp Attack, 168 Speed,
Nature: Mild
- Bolt Strike
- Dragon Claw
- Draco Meteor
- Thunder
This Zekrom set fills in many roles. It's so I can hit around walls and bait the Groudon switch. Also counter's non scarfed Kyurem W/B with the Speed Ev's. If they have a Kyogre you can turn it against them with Thunder. But Groudon still counters it. It's a back-up Physical/Special Sweeper when any of the team goes down.

Arceus-Dark @ Dread Plate (whole set is tweaked)
Ability: Multitype
EVs: 224 Sp Attack, 224 Speed, 60 Hp
Nature: Modest
- Calm Mind
- Judgement
- Flamethrower
- Recover
My main counter to Lugia. Whenever Arecus-Dark comes in they assume I have Refresh over Flamethrower, so they switch in Ferrothorn not knowing I have Flamethrower and BAM!!! However Blaziken becomes a problem so I have to switch. This mighty Dark Lord will make all Lugia's fear it! Giratina won't stand to defeat it either!

Giratina @ Leftovers
Ability: Pressure
EVs: 200 Defense, 200 Sp Defense, 108 Sp Attack
Nature: Modest
- Calm Mind
- Dragon Pulse
- Rest
- Sleep Talk
It walls many and can set up Calm Minds to fight offensively. Though getting up Sub on Giratina is the problem to this set, Kyurem is the problem as well. Ferrothorn checks it completely. It surprises other Giratina walls by setting up Calm Minds and hitting hard. Mewtwo can be walled, but only done right if Giratina set up a few Calm Minds already.

Mewtwo @ Leftovers
Ability: Pressure
EVs: 128 Sp Attack, 128 Speed, 252 Hp
Nature: Bold
- Calm Mind
- Fire Blast
- Recover
- Psystrike
This Mewtwo blasts Ferrothorn and Forretress with Fire Blast and Psystrike to counter Blissey. Physical attackers gives it problems. The HP investment is so it has some bulk and take hits. Mewtwo is fast as already it is. So a some Speed investment and some Sp Attack investment, with the side of max Hp, makes it pretty bulky.

Forretress @ Leftovers
Ability: Sturdy
EVs: 232 Defense, 232 Sp Defense, 42 Attack
Nature: Careful
- Rapid Spin
- Bug Bite
- Stealth Rocks
- Volt Switch
Just a Rapid Spinner and Stealth Rock user. But it has the other role to break the Sash for Deoxys-A ond other formes. Volt Switch to get the switch initiative. Forretress is the huge wall to Physical Pokes, with Bug Bite along side it can hit Mewtwo hard to put it within Revenge Killer range. And Bug Bite is for predicted Taunt users, which kinda works if Mewtwo has Taunt.
Still under testing, making some of those tweaks. The Ev spread is put accordingly.