Hello, I've been testing this on the PO server and Smogon server.
This is relatively a new team, but I've had great success with it so far. Yeah, that's all I have to say.
This is relatively a new team, but I've had great success with it so far. Yeah, that's all I have to say.

Groudon @ leftovers
Nature: Adamant
Ability: Drought
EV: 192 | 192 | 0 | 0 | 0 | 124
Moves: Earthquake ~ Stone-Edge ~ Fire Punch ~ Rock Polish
My main goal for groudon is to set up sun. Then depending on the lead I would either switch in or rock polish and sweep. Fire punch and stone-edge are for coverage and that annoying ferrothorn. Earthquake is for stab. With the one rock polish and the speed evs invested, groudon reaches a blistering 494. This allows it to outspeed a scarfted timid palkia by 2 evs. Also, the extra speed allows me to outspeed other groudons with 4 less speed evs. I divided the rest of the evs into attack and defense. Groudon's greatest weakness is giratina and giratina-o. Giratina cripples with will-o-wisp and walls all it's attacks. Palkia can revenge kill giratina, but risks crippling it's self with a -2 in sp.attack.

Arceus @ leftovers
Nature: Adamant
Ability: Multi-type
EV: 240 | 252 | 0 | 0 | 0 | 16
Moves: Extremespeed ~ Swords Dance ~ Overheat ~ Shadow Claw
Well, if you can't beat them, join them.
This is a pretty standard arceus set. The 16 evs in speed are to outspeed other standard arceus. The theory is to set up swords dance and sweep from there with extremespeed and shadow claw. The reason I don't go with shadow force is the switch ins. For example, I would use shadow force on giratina and they would switch in with dialga. Also a substitute could be set up to stall be out of pp. The only difference between this set and others is overheat. In most cases, brick break is used here, but people switched in Fortress or Ferrethorn which would wall arceus or stall it with rocky helmet and iron barbs. Since hopefully, sun is set up, overheat can without a doubt, KO ferrethron and bring Fortress to 1. Arceus's doesn't have many problems excpet for it's own kind. Any physical arceus or a giratina with will-o-wisp can damage greatly or cripple with will-o-wisp.
This is a pretty standard arceus set. The 16 evs in speed are to outspeed other standard arceus. The theory is to set up swords dance and sweep from there with extremespeed and shadow claw. The reason I don't go with shadow force is the switch ins. For example, I would use shadow force on giratina and they would switch in with dialga. Also a substitute could be set up to stall be out of pp. The only difference between this set and others is overheat. In most cases, brick break is used here, but people switched in Fortress or Ferrethorn which would wall arceus or stall it with rocky helmet and iron barbs. Since hopefully, sun is set up, overheat can without a doubt, KO ferrethron and bring Fortress to 1. Arceus's doesn't have many problems excpet for it's own kind. Any physical arceus or a giratina with will-o-wisp can damage greatly or cripple with will-o-wisp.

Giratina @ Kasib Berry
Nature: Careful
Ability: Pressure
EV: 240 | 0 | 16 | 0 | 244 | 8
Moves: Will-o-Wisp ~ Substitute ~ Dragon Tail ~ Shadow Sneak
My main use of giratina is to wall everything. Basically, I gave it the evs to sustain hits from speacial attackers, and will-o-wisp cripples physical attackers. Substitue allows me to stall out shadow force. I also set up a sub after I've crippled a pokemon with will-o-wisp, and then dragon tail and see if I can continue crippling physical attackers. Also it allows me to rack up any hazard damage that was bounced. While I have used leftovers, Kasib berry ensures that if it switches into a +2 arceus I will survive two shadow claws. (Will-o-wisp misses a lot). Dragon tail is for getting rid of those pesky calm mind kyogres, mewtwos, arceus, etc. Giratina's greatest problem is lugia which outspeeds and either uses toxic or t-wave. Lugia wears it down, and recovers with roost. Espeon deals with lugia well, unless it's the dragon tail variant.
Palkia @ Choice scarf
Nature: Timid
Ability: Pressure
EV: 0 | 0 | 6 | 252 | 0 | 252
Moves: Thunder ~ Draco Meteor ~ Spacial Rend ~ Aura Sphere
Simple, but effective scarfted Palkia. It's job is to revenge kill or put a whole in the other team. Thunder is for kyogre. Draco meteor KO's most of the Darkrai I have encountered. However, it does give the opponent a free switch in because after that one use, palkia's basically useless. Spacial rend is there for palkia to spam without giving the opponent an advantage. I wasn't sure about the last move slot. I was having trouble with dialga, so I just aura sphere there. I have tried fire blast, but I don't like the accuracy. Flamethrower might be a good substitue, but that leaves me with no way to damage dialga significantly without using draco meteor which is a last resort. Aura sphere does take care of tyranitar though and it's a last resort for ferrothorn. Palkia's main problem is wobbuffet and chansey/blissey. Espeon can ignore all and giratina can set up sub to block status or dragon tail.

Ludicolo @ Leftovers
Nature: Calm
Ability: Rain Dish
EV: 252 | 0 |40 | 0 | 216 | 0
Moves: Leech Seed ~ Ice Beam ~ Protect ~ Toxic
My favorite set. Ludicolo can stall from the earth to the moon and back. I switch this in on kyogre or any other special attacker, and watch as it reaps. Protect is to ensure that ludicolo can take a draco meteor from dialga and palkia, and recover so that it can survive another. Toxic helps ludicolo stall longer. I've tested ferrothorn, and it doesn't resist water spout as well as ludicolo and is 2 ohko. Ice beam is for coverage. Ludicolo's biggest problem is physical attackers like Ho-oh and +2 arceus. Giratina can wall arceus, but I have a tough time with Ho-oh.

Espeon @ Leftovers
Nature: Timid
Ability: Magic Bounce
EV: 0 | 0 | 6 | 252 | 0 | 252
Moves: Calm Mind ~ Hp Fire ~ Psychic ~ Shadow Ball
Two underused in an ubers team????
Espeon is actually very affective in it's job. With lead darkrai, phasers, and cripplers, I send espeon out to bounce back the entry hazards and status. Hidden power fire is for ferrothorn, skarmmory, etc. Then I set up calm mind and sweep. It's problem would be power whip and gyro ball, but I switch giratina to will-o-wisp. Espeon, is also, a suprising late game sweeper. It's main downfall is ttar who walls it with a +1 sp.defense in sandstorm and KOs with pursuit. Groudon comes in to wall and revenge kill.
Espeon is actually very affective in it's job. With lead darkrai, phasers, and cripplers, I send espeon out to bounce back the entry hazards and status. Hidden power fire is for ferrothorn, skarmmory, etc. Then I set up calm mind and sweep. It's problem would be power whip and gyro ball, but I switch giratina to will-o-wisp. Espeon, is also, a suprising late game sweeper. It's main downfall is ttar who walls it with a +1 sp.defense in sandstorm and KOs with pursuit. Groudon comes in to wall and revenge kill.