Silly DNA (Deoxys-Attack) @ Life Orb
Ability: Pressure
EVs: 4 Atk / 252 SAtk / 252 Spd
Hasty Nature
IVs: 30 HP
- Fire Punch
- Thunderbolt
- Ice Beam
- Psycho Boost
RC_4777 (Arceus) @ Draco Plate
Ability: Multitype
EVs: 252 HP / 252 SAtk / 4 SDef
Modest Nature
- Calm Mind
- Judgment
- Flamethrower
- Earth Power
Raymond (Rayquaza) @ Persim Berry
Ability: Air Lock
EVs: 252 HP / 252 Atk / 4 SDef
Adamant Nature
- Outrage
- Earthquake
- Fly
- Extreme Speed
i cri (Darkrai) @ Life Orb
Ability: Bad Dreams
EVs: 252 SAtk / 4 SDef / 252 Spd
Timid Nature
- Dark Void
- Dark Pulse
- Dream Eater
- Nasty Plot
DJTheChad (Dialga) @ Leftovers
Ability: Pressure
EVs: 252 HP / 252 SAtk / 4 SDef
Modest Nature
- Aura Sphere
- Earth Power
- Flash Cannon
- Dragon Pulse
MooTwo (Mewtwo) @ Wise Glasses
Ability: Unnerve
EVs: 252 SAtk / 4 SDef / 252 Spd
Timid Nature
- Aura Sphere
- Flamethrower
- Psystrike
- Thunderbolt
I can't say I know much about Ubers, but I can give you some basic fixes.
Deoxys-A -> Aegislash (you're weak to Xerneas) @ Leftovers 252 Atk 252 HP 4 SpDef -Kings Shield -Gyro Ball -Shadow Sneak -Sacred Sword
Arceus-Dragon -> Arceus-Ghost @ Spooky Plate 252 HP 4SpA 252 Speed Timid -Calm Mind -Judgement -Focus Blast -Recover
Dream Eater -> Focus Blast on Darkrai
Earth Power -> Stealth Rock on Dialga 252 HP 56 SpA 200SpDef
Rayquaza -> Zekrom @ Choice Scarf (kind of need an Yveltal check) 252 Atk 252 4SpA Jolly -Bolt Strike -Volt Switch -Outrage -Dragon Claw
Mewtwo -> Mewtwo @ Mewtwonite Y -Psystrike -Fire Blast -Ice Beam -Taunt