My best Ubers Team So far

Magerna (Magearna) @ Leftovers
Ability: Soul-Heart
EVs: 248 HP / 8 Def / 252 SpD
Calm Nature
IVs: 0 Atk / 29 Spe
- Fleur Cannon
- Volt Switch
- Heart Swap
- Pain Split

Gyro (Giratina-Origin) @ Griseous Orb
Ability: Levitate
EVs: 252 Def / 252 SpA / 4 SpD
Quiet Nature
- Shadow Sneak
- Draco Meteor
- Will-O-Wisp
- Defog

Grudon (Groudon) @ Red Orb
Ability: Drought
EVs: 152 HP / 232 Atk / 44 SpD / 80 Spe
Adamant Nature
- Stealth Rock
- Precipice Blades
- Rock Polish
- Fire Punch

Toys-RC-Us (Arceus-Rock) @ Stone Plate
Ability: Multitype
EVs: 160 HP / 4 Def / 148 SpA / 196 Spe  <- outspeeds the RCus that run 1 speed more than Lucario ;]
Timid Nature
IVs: 0 Atk
- Calm Mind
- Judgment
- Recover
- Fire Blast

Yveltal @ Choice Scarf
Ability: Dark Aura
EVs: 32 HP / 232 SpA / 244 Spe  <- out speeds mega mewtwo y
Modest Nature
- Dark Pulse
- Oblivion Wing
- Toxic
- U-turn

Kroger (Kyogre) @ Blue Orb
Ability: Drizzle
EVs: 248 HP / 252 Def / 8 SpA
Bold Nature
IVs: 0 Atk / 8 Spe  <- under speeds sassy Groudon leads
- Scald
- Ice Beam
- Rest
- Sleep Talk