Team Build Help

[Sevynn]

Been a long time since I've posted, so I figure I'll post up my team.

Froslass @ Focus Sash
Ability: Cursed Body
EVs: 252 HP / 4 SpA / 252 Spe
Timid Nature
- Hex
- Thunder Wave
- Destiny Bond
- Taunt

Froslass acts as my lead, using Taunt to disrupt opposition from setting up, Taunting, defog etc. Thunder Wave to slow down fast pokemon for her team mates, also works together with Hex.

Jolteon (M) @ Zap Plate
Ability: Volt Absorb
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature
- Shadow Ball
- Thunder
- Volt Switch
- Roar

Jolteon, my fast sweeper. I have him holding a Zap plate I know xD; Maybe I should have him hold Life Orb instead ?

Charizard (M) @ Charizardite X
Ability: Blaze
EVs: 4 HP / 252 Atk / 252 Spe
Adamant Nature
- Dragon Claw
- Dragon Dance
- Protect
- Flare Blitz

Sylveon (F) @ Leftovers
Ability: Pixilate
EVs: 252 HP / 252 SpA / 4 SpD
Modest Nature
- Hyper Beam
- Wish
- Moonblast
- Psyshock

Swampert (M) @ Rocky Helmet
Ability: Torrent
EVs: 252 HP / 80 Atk / 172 Def / 4 SpD
Adamant Nature
- Waterfall
- Rock Slide
- Hammer Arm
- Wide Guard

My problem with Swampert, is that he's quite slow. Maybe I should work with a different build? Every time I'm in Doubles, he's usually ganged up on. ;-;
I do have a Greninja I've fully trained as well, but my team lacks phys def.

Latias (F) @ Life Orb
Ability: Levitate
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature
- Light Screen
- Draco Meteor
- Calm Mind
- Psyshock

I have other pokemon in mind aswell, but I wanted to get any advice on what I have currently. My team is pretty squishy ;-; It's mainly for doubles/multi-battles. I honestly think I'm quite bad at putting together a team, I usually just put or try to put my favs and work around that.

Also, here is what I've got in my Battle box...I've been wanting to try to create a somewhat successful Eeveelution team. So any tips and advice here will definitely help out a lot.

Sylveon (F) @ Rocky Helmet
Ability: Pixilate
EVs: 252 HP / 4 SpA / 252 SpD
Calm Nature
- Draining Kiss
- Hyper Beam
- Wish
- Protect

Umbreon (M) @ Leftovers
Ability: Synchronize
EVs: 252 HP / 4 Atk / 252 SpD
Careful Nature
- Yawn
- Payback
- Moonlight
- Curse

Originally had Toxic in there, but Yawn has been working well for me. (so far xD; )

Jolteon @ Zap Plate
Ability: Volt Absorb
EVs: 4 HP / 252 SpA / 252 Spe
Modest Nature
- Thunderbolt
- Shadow Ball
- Roar
- Thunder Wave

Thunder wave to slow down fast enemies, Roar to switch out a potential hazard.

Flareon (F) @ Toxic Orb
Ability: Guts
EVs: 252 Atk / 252 Spe
Adamant Nature
- Facade
- Flame Charge
- Rest
- Sleep Talk

Ah Flareon ;u; He's really amazing, but one good water move will end him. He's my main phys attacker with Facade. Flame Charge on those weak to it, and it gives him a nice speed boost. If he has too little health, Rest and then Sleep Talk.

Espeon (F) @ Light Clay
Ability: Magic Bounce
EVs: 252 HP / 4 SpA / 252 Spe
Naive Nature
- Reflect
- Psyshock
- Dazzling Gleam
- Light Screen

Invested mainly into Speed so she can set up screens as soon as possible. HP investment is also to give her that bulk while she's setting up screens. Wasn't sure whether or not to keep Dazzling Gleam, it doesn't do much at all and seems like a wasted slot. I thought of Yawn but that is already used on my Umbreon.

Vaporeon @ Sitrus Berry
Ability: Water Absorb
EVs: 252 HP / 252 Def / 4 SpA
Bold Nature
- Scald
- Wish
- Protect
- Ice Beam

Vaporeon; mainly a phys sponge of sorts as her role is to pass Wishes.

Overall, I'm not sure with this team. I have levelled and EV trained a Leafeon, but wasn't sure where to fit her in because of her weaknesses. But I have read and seen what she can be capable of. Her details are like so:

Leafeon @ Life Orb
Ability: Leaf Guard
EVs: 252 HP / 252 Atk / 4 Spe
Jolly Nature
- Swords Dance
- Leaf Blade
- X-Scissor
- Grass Whistle​

 

[PlatinumDude]

Note: this team is rated assuming it was a singles team. Take note that in doubles, Protect/Detect is a mandatory option for non-Choice/Assault Vest users because of its wide utility in punishing double-targeting, scouting or giving the partner time to take out a threat.

Gengar makes a better stall breaker than Froslass, IMO, as it has more power behind its Hexes:
-Hex
-Taunt
-Will-o-Wisp
-Sludge Wave/Sludge Bomb/Substitute
Nature: Timid
EVs: 8 HP/248 SAtk/252 Spe
Item: Black Sludge

Umbreon isn't really cutting it for the team, IMO. Mandibuzz does what it can do better; it doesn't fall prey to Bug and Fighting attacks as easily:
-Foul Play
-Roost
-Taunt/Whirlwind
-Toxic/Defog/Knock Off
Nature: Bold/Impish
EVs: 248 HP/136 Def/108 SDef/16 Spe
Item: Leftovers
Ability: Overcoat

Jolteon is outclassed by other Electric Pokemon like Wash Rotom, simply because it doesn't have much utility compared to them. Offensively, Jolteon pales in comparison to other offensive Electrics like Mega Manectric, but it's not an option because you already have a Mega in Charizard. Don't forget that Roar has negative priority, and that's not good considering Jolteon's overall frailty. If you want a fast special attacker, look no further than Greninja, Keldeo or Latios:

Wash Rotom:
-Volt Switch
-Hydro Pump
-Will-o-Wisp
-Pain Split/Rest
Nature: Bold/Calm
EVs: 248 HP/216 Def/44 Spe (Bold) or 248 HP/216 SDef/44 Spe (Calm)
Item: Leftovers/Chesto Berry

or
-Volt Switch
-Hydro Pump
-Thunderbolt/Will-o-Wisp/Hidden Power (Ice)
-Trick
Nature: Timid/Modest
EVs: 4 HP/252 SAtk/252 Spe
Item: Choice Scarf

Greninja:
-Hydro Pump
-Ice Beam
-Grass Knot/Hidden Power (Grass)/Gunk Shot (latter is an option in OR/AS server in Pokemon Showdown!, if this is a Showdown! team)
-Hidden Power (Fire)/Dark Pulse/Extrasensory
Nature: Timid/Naive
EVs: 4 HP/252 SAtk/252 Spe or 40 Atk/216 SAtk/252 Spe
Item: Life Orb
Ability: Protean

or
-Spikes
-Hydro Pump
-Ice Beam/Dark Pulse
-Dark Pulse/Grass Knot/Hidden Power (Grass)
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Life Orb
Ability: Protean

Keldeo:
-Hydro Pump
-Secret Sword
-Scald
-Icy Wind/Hidden Power (Flying/Electric)
Nature: Timid
EVs: 252 SAtk/4 SDef/252 Spe
Item: Life Orb/Choice Specs/Choice Scarf

or
-Calm Mind
-Hydro Pump/Scald
-Secret Sword
-Hidden Power (Flying)/Substitute
Nature: Timid
EVs: 252 SAtk/4 SDef/252 Spe
Item: Life Orb/Leftovers

or
-Substitute
-Hydro Pump/Scald
-Secret Sword
-Endeavor
Nature: Timid
EVs: 8 HP/248 SAtk/252 Spe
Item: Salac Berry

Latios:
-Draco Meteor
-Psyshock
-Hidden Power (Fire)/Surf/Earthquake
-Roost/Recover/Defog
Nature: Timid/Hasty
EVs: 252 SAtk/4 SDef/252 Spe
Item: Life Orb

or
-Draco Meteor
-Psyshock
-Hidden Power (Fire)/Tailwind/Defog
-Trick
Nature: Timid
EVs: 4 HP/252 SAtk/252 Spe
Item: Life Orb

Flareon sucks, simply put. Its shallow move pool is what ruins it, even with the addition of Flare Blitz. Heck, I'd even consider Entei before Flareon, tbh, since the addition of Sacred Fire is what makes it good, or even Heatran, who has a plethora of resistances to make up for its common weaknesses:
-Sacred Fire
-Extreme Speed
-Stone Edge
-Bulldoze
Nature: Adamant
EVs: 252 Atk/4 SDef/252 Spe
Item: Choice Band/Life Orb

Heatran:
-Lava Plume
-Toxic
-Taunt/Earth Power/Roar
-Protect/Stealth Rock/Earth Power
Nature: Calm
EVs: 248 HP/192 SDef/68 Spe
Item: Leftovers

or
-Overheat/Fire Blast
-Flash Cannon/Hidden Power (Ice)
-Earth Power/Flamethrower
-Stone Edge/Ancient Power
Nature: Modest/Timid
EVs: 252 SAtk/4 SDef/252 Spe
Item: Choice Scarf

or
-Stealth Rock
-Fire Blast/Flamethrower
-Taunt
-Will-o-Wisp/Toxic/Earth Power/Flash Cannon
Nature: Timid/Modest
EVs: 12 HP/252 SAtk/244 Spe
Item: Air Balloon

If you can't use either, use Infernape instead:
-Fire Blast/Flare Blitz
-Close Combat
-Mach Punch
-Thunder Punch/Hidden Power (Ice)/Grass Knot
Nature: Hasty/Naive
EVs: 168 Atk/88 SAtk/252 Spe
Item: Life Orb
Ability: Iron Fist

or
-Stealth Rock
-Overheat
-Close Combat
-Endeavor
Nature: Hasty/Naive
EVs: 168 Atk/88 SAtk/252 Spe
Item: Focus Sash
Ability: Blaze

or
-Close Combat
-Will-o-Wisp
-Taunt
-Slack Off
Nature: Impish
EVs: 212 HP/4 Atk/252 Def/40 Spe
Item: Leftovers
Ability: Blaze

Swampert is meh, currently simply because the power creep was too much for it. Gastrodon and Quagsire are generally the better alternatives because of their access to reliable recovery:

Gastrodon:
-Scald
-Earthquake/Earth Power/Ice Beam
-Toxic
-Recover
Nature: Relaxed/Bold
EVs: 252 HP/252 Def/4 SDef
Item: Leftovers
Ability: Storm Drain

Quagsire:
-Scald
-Earthquake
-Toxic
-Recover
Nature: Relaxed
EVs: 252 HP/252 Def/4 SDef
Item: Leftovers
Ability: Unaware

In singles, there's no need for Charizard X to use Protect:
-Dragon Dance
-Flare Blitz
-Dragon Claw
-Roost
Nature: Adamant
EVs: 96 HP/252 Atk/160 Spe
Item: Charizardite X
Ability: Blaze

Hyper Beam seems tempting, but it's a bad option because it leaves the user as a sitting duck the next turn. Hyper Voice is the preferred option over it. If you want it, you can either transfer over an Anticipation Eevee with Hyper Voice from Black 2/White 2, or wait until Omega Ruby/Alpha Sapphire, where Hyper Voice becomes a move tutor again:
-Wish
-Protect
-Hyper Voice
-Heal Bell
Nature: Bold
EVs: 252 HP/216 Def/40 SDef
Item: Leftovers
Ability: Pixilate

or
-Hyper Voice
-Shadow Ball
-Psyshock
-Baton Pass/Hidden Power (Ground/Fire)/Protect (if doubles)
Nature: Modest
EVs: 244 HP/252 SAtk/12 Spe
Item: Choice Specs/Sitrus Berry (latter if doubles)
Ability: Pixilate

As for your Battle Box:

For Sylveon, the tips I said in your main team applies to this Battle Box team as well.

Dazzling Gleam on Espeon is mainly for Dark Pokemon, who wall it otherwise.

What I said about Roar for Jolteon in the above team also applies to this team. Jolteon is just too frail to use Roar. If you want to use Jolteon, try this:
-Thunderbolt
-Volt Switch
-Hidden Power (Water)
-Signal Beam/Shadow Ball
Nature: Timid
EVs: 252 SAtk/4 SDef/252 Spe
Item: Life Orb/Choice Specs
Ability: Volt Absorb

As I mentioned before, Flareon's offensive move pool is lacking; also its defensive typing is pretty bad, but still, it can pull off support sets (or the occasional offensive one, but that needs Superpower, a tutor move, to work effectively) somewhat decently:
-Wish
-Protect
-Flare Blitz/Lava Plume
-Roar/Will-o-Wisp
Nature: Careful/Calm
EVs: 248 HP/8 Def/252 SDef
Item: Leftovers
Ability: Flash Fire

or
-Flare Blitz
-Superpower
-Quick Attack
-Sleep Talk/Baton Pass
Nature: Adamant
EVs: 252 Atk/4 SDef/252 Spe
Item: Choice Band/Charcoal/Flame Plate

Foul Play is pretty much a requirement for Umbreon, as its offensive stats are very weak:
-Wish
-Protect
-Foul Play
-Heal Bell/Toxic
Nature: Calm
EVs: 252 HP/4 Def/252 SDef
Item: Leftovers
Ability: Synchronize