Starting out with an... interesting team

Just as it says in the title, I'd like to see the competitive battling scene, and I'm doing it with a team of favorites. Most of them seem to be in the NU part of the game, but that just makes it all the more appealing. I haven't used this team just yet in an actual battle, but I'm willing to accept challenges from people interested. Please rate!

Anyhow, my team so far:


Pokemon 1: Maple the Gardevoir

Ability: Synchronize
Nature: Timid
Item: Lum Berry
EVs: 252 Speed/4 Def/252 Hp
Moves:
- Thunder Wave
- Heal Pulse
- Reflect
- Psychic/Psyshock




Pokemon 2: Dontae the Shuckle

Ability: Sturdy
Nature: Bold
Item: Leftovers
EVs: 252 Def/4 Sp.Def/252 Hp
Moves:
- Rest
- Sleep Talk
- Toxic
- Flash




Pokemon 3: Angel the Umbreon

Ability: Synchronize
Nature: Careful
Item: Leftovers (Focus Sash if multiple items aren't allowed)
EVs: 252 SP.Def/4 Def/252 Hp
Moves:
- Moonlight
- Confuse Ray
- Protect
- Roar




Pokemon 4: Rarukaria the Lucario

Ability: Steadfast
Nature: Adamant
Item: Choice Scarf (at least until I get the Choice Band)
EVs: 252 Atk/4 Hp/252 Speed
Moves:
- Blaze Kick
- Ice Punch
- Close Combat
- Aura Sphere/ExtremeSpeed




Pokemon 5: Skitter the Galvantula

Ability: Compoundeyes (wish it was unnerve, but oh well)
Nature: Timid
Item: Bug Gem (Maybe at least until I get Choice Specs)
EVs: 252 Speed/4 Hp/252 Sp.Atk
Moves:
- Discharge
- Bug Buzz
- Energy Ball
- Volt Switch




Pokemon 6: Slug the Slaking

Ability: Traunt
Nature: Adamant
Item: Normal Gem
EVs: 252 Atk/4 Hp/252 Speed
Moves:
- Aerial Ace
- Retaliate
- Slack Off
- Brick Break

Most of your team is easily susceptible to Taunt, particularly Shuckle and Umbreon. (I'll let someone else suggest sets or replacements for them)

I'd give Gardevoir Wish instead of Heal Pulse since it only benefits the opponent in Singles.

Also, I'd make Lucario this:
-Swords Dance
-Close Combat
-Crunch/Ice Punch
-ExtremeSpeed/Ice Punch
Nature: Adamant/Jolly
EVs: 252 HP/4 Def/252 Spe
Item: Life Orb

or
-Nasty Plot
-Aura Sphere
-Dark Pulse
-Vacuum Wave/Hidden Power (Ice)/Dragon Pulse
Nature: Modest/Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Life Orb

Since Galvantula has CompoundEyes (which is good), I'd have Thunder over Discharge to take advantage of the ability.

Also, Slaking really sucks competitively because of its ability. Even though Archeops has an equally bad ability, I'd say that it's a bit better than Slaking to an extent:
-Stone Edge/Rock Slide
-Acrobatics
-Earthquake
-U-turn/Hidden Power (Ice)
Nature: Jolly/Naive
EVs: 252 Atk/4 Def or SAtk/252 Spe
Item: Flying Gem

Thanks for the suggestions. I'm making some changes as we speak :0

I'd say scratch Slaking, and use an Ursaring.

Ursaring @ Flame Orb
252 Hp/252 Att/4Spd. Jolly natured.

-EQ
-Facade
-Rest
-Swords Dance

@Zadikal I prefer Slaking over Ursaring, but he's now out of my team. Thanks for replying, though :3

@Alexial357 Thanks for your help, too. For Skarmory, I saw the bad synergy that it would cause, and decided to use Cofagrigus instead. With my revamped team, it seems Cofagrigus makes the synergy almost perfect. I don't have entry hazards included on my team, but I may give Stealth Rock to Blissey, whom I'll replace with Gardevoir for the time being.

There's no way I wouldn't rate a team with a Shuckle named Dontae.

Firstly, I'm going to break some hard news to you, you can't always win with your favorites, even in the lowest of tiers, some Pokemon are just more viable than others. NU Pokemon hardly have a place in OU, and even if it seems that a 'unique' team can still win, it honestly can't, even with the most experienced of players manning it. If you're serious about using this team in OU play, then hopefully you accept the following changes.

Alright, so it seems like Gardevoir is taking the role of status absorber and the team's Psychic type, well you're in luck, there's a Pokemon that outclasses Gardevoir in doing so, and can rip apart unrpepared teams.

Sigilyph @ Flame Orb
Ability: Magic Guard
Nature: Bold
EVs: 252 HP / 112 Def / 88 SpD / 56 Spe

-Stored Power
-Cosmic Power
-Roost
-Psycho Shift

So basically, Sigilyph takes no damage from the Flame Orb, and Psycho Shift allows you to give your status [Burn] to your opponent. This is vital to Sigilyph's success and the first thing you should do when you have it in. A burned Pokemon has its attack halfed, so things that normally rely on Physical damage to beat Sigilyph, like Jirachi and Tyranitar, won't stand a change against it. Next, you keep using Cosmic Power to boost your defenses, so that no Pokemon will be able to harm you, which is easily aided via Psycho Shift, since a burned Pokemon will have a hard time damaging you already. Once you've accumulated 6 Cosmic Powers, then you unleash Stored Power, which does more damage for each stat boosts you have, and at +6/+6, it will be doing a ton. Don't worry about Dark Types, at this point, they won't be able to touch you because of your boosted defenses, so just Psycho Shift them a burn and stall them out with Roost. The only Pokemon that truly, truly walls this set is Houndoom, which is nearly nonexistent in OU play, but watch out for it if you're using Sigilyph in UU.

If you choose to use Cofagrigus like you say, then I reccomend using it as a dedicated Physical wall, since Physical Attackers, specifically Dragons seem to rip through you

Cofagrigus @ Leftovers
tem: Leftovers
Ability: Mummy
Nature: Bold
EVs: 252 HP / 252 Def/ 4 SDef
- Shadow Ball
- Will-O-Wisp
- Haze
- Rest

Rest goes great on Cofagrigus, since it's Cofa's only Healing option, and Blissey can use Aromatherapy to absolve it of its Sleep Status. Honestly, I think Skarmory is a much better option, but Cofagirgus is still a good Physical Wall.

For Lucario, I reccomend using Platinumdude's set, just remember to include Ice Punch, otherwise things like Gliscor and Hippowdon will wall the set with ease.

Finally, for Galvantula, use this set

Galvantula @ Life Orb
Item: Life Orb
Ability: Compoundeyes
Nature: Timid
EVs: 4 Def / 252 SpA / 252 Spe
IVs: 31 / 30 / 30 / 31 / 31 / 31
-Thunder
-Bug Buzz
-Volt Switch
-Hidden Power Ice

The IVs above are needed to get Hidden Power Ice, which is pretty much essential to this set, as Gliscor will run over your team otherwise. There is no risk in running Thunder, really, because Compoundeyes really helps with the accuracy and the base power boost, so even if your Galvantula is unnerve, I highly reccomend you catch one with Compoundeyes, otherwise, it will either need Rain Support for Thunder, or will just be a tad less effective and use Thunderbolt over Thunder.

Slaking is powerful, but it really isn't a Pokemon worth using, because of the value of a free turn in the Metagame. Slaking also lacks the speed to effectively revenge kill [unless you plan on giving it a Choice Scarf], Slaking is really just a bad gimmick. In turn, I reccomend using Scarf Landorus or Scarf Terrakion. Scarf Terrakion is probably the better option, but is absolutely laughed at by Gliscor, so taking out Gliscor will be top priority if you hope to use Terrakion to revenge kill to its best ability. Anyhow, the sets for both are as follows:

Terrakion @ Choice Scarf
Ability: Justified
Nature: Jolly
EVs: 4 HP / 252 Atk / 252 Spe
-Stone Edge
-Close Combat
-Earthquake
-X-Scissor

Also, if you predict a Dark Type attack being used against one of your Pokemon, switch in Terrrakion, because its ability will give it an attack boost.

As for Landorus:

Landorus @ Choice Scarf
Ability: Sand Force
Nature: Naive
EVs: 4 Def / 252 SpA / 252 Spe
IVs: 31 / 30 / 30 / 31 / 31 / 31
-Stone Edge
-Earthquake
-Hidden Power Ice
-U-Turn

Hidden Power Ice crushes Gliscor and U-Turn crushes things like Latias and allows you to gain an advantage by using it on a predicted switch, allowing you to get your appropriate counter in.