Battling thread... Thing

Hello people. I'm just here to talk about competitive battling. I have battled competitively for a long time soo yeah....
My usual pokemon:
Scizor: x Scizor, swords dance, u turn,niron head

Weavile:ice punch,dark pulse,areial ace, surf

Kingdra: dragon dance, dragon pulse, hydro pump and Draco meteor

Hydreigon: Draco meteor, flame thrower, dragon tail, dragon dance

Chandelure: fire blast, night slash, shadow ball, will o wisp

Ad my trolleon uh I mean umbreon: toxic, protect, substitute, rest>_>

I mean iron head. For Scizor sorry.

EVs and natures would totally be helpful here, man. These are CRUCIAL to competitive battling.

Anyway, Weavile should focus on physical attacking, as Ash already pointed out. It's risky to use in OU because of its common weaknesses and low defenses:
-Pursuit
-Ice Shard
-Ice Punch/Night Slash
-Low Kick
Nature: Jolly
EVs: 32 HP/252 Atk/224 Spe
Item: Life Orb/Choice Band
Ability: Pressure

or
-Swords Dance
-Ice Shard/Ice Punch
-Night Slash
-Low Kick
Nature: Jolly
EVs: 32 HP/252 Atk/224 Spe
Item: Life Orb
Ability: Pressure

None of Kingdra's moves benefit from Dragon Dance's Attack boost:
-Rain Dance
-Hydro Pump/Surf
-Draco Meteor
-Surf/Ice Beam/Dragon Pulse
Nature: Modest
EVs: 40 HP/240 SAtk/228 Spe
Item: Life Orb
Ability: Swift Swim

or
-Substitute
-Dragon Dance
-Waterfall
-Outrage
Nature: Adamant
EVs: 40 HP/228 Atk/12 Def/228 Spe
Item: Leftovers
Ability: Swift Swim

or
-Draco Meteor
-Hydro Pump
-Dragon Pulse/Ice Beam
-Surf/Ice Beam
Nature: Modest
EVs: 28 HP/252 SAtk/228 Spe
Item: Choice Specs
Ability: Swift Swim

or
-Dragon Dance
-Waterfall
-Outrage
-Rest
Nature: Adamant
EVs: 152 HP/96 Atk/32 SDef/228 Spe
Item: Chesto Berry
Ability: Swift Swim

or
-Dragon Dance
-Waterfall/Hydro Pump
-Outrage
-Draco Meteor/Hidden Power (Fire)
Nature: Lonely/Naughty
EVs: 136 Atk/136 SAtk/236 Spe
Item: Life Orb/Lum Berry
Ability: Swift Swim

Hydreigon can't learn Dragon Dance. It has an extremely wide movepool, so take advantage of it:
-Draco Meteor
-Fire Blast
-Superpower
-Earthquake/Earth Power/Dark Pulse/Roost
Nature: Rash/Mild
EVs: 4 Atk/252 SAtk/252 Spe
Item: Life Orb/Expert Belt

or
-Substitute
-Dragon Pulse
-Focus Blast
-Fire Blast/Roost
Nature: Modest
EVs: 4 HP/252 SAtk/252 Spe
Item: Leftovers/Life Orb

or
-Draco Meteor
-Fire Blast
-Focus Blast
-U-turn/Dark Pulse
Nature: Modest
EVs: 4 HP/252 SAtk/252 Spe
Item: Choice Specs

Chandelure can't learn Night Slash. See what moves a Pokemon can and can't learn before coming up with move sets:
-Substitute
-Fire Blast
-Shadow Ball
-Hidden Power (Fighting)/Pain Split
Nature: Timid/Modest
EVs: 4 HP/252 SAtk/252 Spe
Item: Leftovers/Life Orb
Ability: Flash Fire

or
-Overheat/Fire Blast
-Shadow Ball
-Hidden Power (Fighting)
-Energy Ball/Trick
Nature: Timid/Modest
EVs: 4 HP/252 SAtk/252 Spe (Timid) or 72 HP/252 SAtk/184 Spe (Modest)
Item: Choice Scarf (Timid)/Choice Specs (Modest)
Ability: Flash Fire

But then again, Gengar does Chandelure's job better:
-Substitute
-Shadow Ball
-Focus Blast
-Disable/Pain Split
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Black Sludge/Life Orb

or
-Substitute/Protect
-Shadow Ball
-Focus Blast
-Hidden Power (Fire)
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Life Orb/Black Sludge

Umbreon is terrible in OU because of its tendency to be used as setup bait. Sableye can do its job better due to Prankster giving priority to its support moves:
-Taunt
-Will-o-Wisp
-Recover
-Foul Play/Night Shade/Snarl
Nature: Calm
EVs: 252 HP/4 Def/252 SDef
Item: Leftovers
Ability: Prankster

If you really want to keep Umbreon, this is the best set it has to use; it can do Wish support:
-Wish
-Protect
-Foul Play
-Heal Bell/Yawn/Toxic
Nature: Calm
EVs: 252 HP/4 Def/252 SDef
Item: Leftovers
Ability: Synchronize

Scizor must always use Bullet Punch; it's very strong priority when paired with Technician:
-U-turn
-Bullet Punch
-Superpower/Brick Break
-Pursuit/Quick Attack
Nature: Adamant
EVs: 248 HP/252 Atk/8 Spe
Item: Choice Band
Ability: Technician

or
-Swords Dance
-Bullet Punch
-Bug Bite
-Superpower/Brick Break
Nature: Adamant
EVs: 252 Atk/4 SDef/252 Spe
Item: Life Orb/Leftovers/Iron Plate
Ability: Technician

or
-Swords Dance
-Bullet Punch
-Bug Bite/Superpower
-Roost
Nature: Adamant
EVs: 252 HP/40 Atk/216 SDef
Item: Leftovers
Ability: Technician

In my opinion your team also needs a rock-type resistance. Despite the fact that Rock-type moves are uncommon in OU, Pokemon like Choice Scarf Tyranitar or Terrakion might be able to plow through your whole team if you're not careful. Ground and Fighting types are the best choices for countering and checking such Rock-types. Fighting-types have the ability to break through Blissey and Chansey, whereas Ground-types can break through Heatran and Magnezone. The choice is yours.