Bastiodon
I would suggest this.
>Bastiodon (M) @ Leftovers
Trait: Sturdy
EVs: 252 HP / 4 Def / 252 SDef
Impish Nature (+Def, -SAtk)
- Iron Head
- Stealth Rock
- Toxic
- Roar
>This would be one of the best if not the best support Pokemon for NU tier. So Iron Head is your Stab.If you get Taunted you wouldn't be cripple.Iron Head is powerful with the chance of making your opponent flinch which is good.Stealth Rock is your entry hazard a good one effects many types.Toxic is a good move poison your foe on top if the HP lost from Stealth Rock this guy is good.Then here is the best part you use Roar to get their team crippled.They all won't have full HP after this and if you use the set right you should be able to poison them.He can take many hits which is very good.
Ariados
>Creppy. (Ariados) (F) @ Black Sludge
Trait: Insomnia
EVs: 4 HP / 252 Atk / 252 Spd
Adamant Nature (+Atk, -SAtk)
- Poison Jab
- Sucker Punch
- Toxic Spikes
- Protect
>I think she would be nice to set up Toxic Spikes.She had better supporting for your team than Muk did in my opinion.Poison Jab is your Stab which can poison your foe always nice to have.Sucker Punch gives your priority and gives nice coverage for Psychic types.Toxic Spikes set up your entry hazard,another reason why I suggested her is for when your foe sets Toxic Spikes on you,Ariados would be nice to send out since she is a poison type her self she can make the Toxic Spikes disappear.Protect is to help from fainting quickly.Black Sludge heals poison types so if your opponent use trick they will suffer not you.
Seaking
>Seaking (M) @ Life Orb
Trait: Lightningrod
EVs: 252 Atk / 92 SAtk / 164 Spd
Lonely Nature (+Atk, -Def)
- Waterfall
- Ice Beam
- Megahorn
- Return
>You already had an two Ice types so I decided to replace one.This Pokemon out classes Walrein,Seaking has the ability Lightingrod which draws in his 1/2 of his weaknesses.Thats faboulous,Waterfall is your Stab has the ability to make your opponent flinch switch which is nice.He only has one weakness now that easily is taken out bye Ice beam and Megahorn.Make sure you put in 255 for his happiness to max out Return. Life Orb is for that extra boost.
Leafeon
>2Bright? (Leafeon) (F) @ Leftovers
Trait: Chlorophyll
EVs: 4 HP / 252 Atk / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Leaf Blade
- X-Scissor
- Aerial Ace
- Swords Dance
>Chlorophyll/Leaf Guard are both very useless here but you will not find something like Leafeon in NU. Leaf Blade is your awesome Stab. X-Scissor is coverage also another great move.Aerial Ace is can be used to take out your Bug weakness.Swords Dance ups your attack enough a couple of those and you could have a Sweeper on your hands. Just tell me if you wan't a replacement for Leafeon.
Masquerain
>Masquerain (M) @ Life Orb
Trait: Intimidate
EVs: 4 HP / 252 SAtk / 252 Spd
Modest Nature (+SAtk, -Atk)
- Bug Buzz
- Air Slash
- Hydro Pump
- Quiver Dance
>What is wonderful about him is he has intimidate and Quiver Dance.While when you start off battle lowering your opponents Stats hurts but along with that Quiver Dance ups three of Masquerain's. He is an awesome Special Attacker he gets Stabs from Bug Buzz and Air Slash.He learns a powerful water attack Hydro Pump which is nice.
Lampent
>Lampent (M) @ Eviolite
Trait: Flame Body
EVs: 252 HP / 4 Def / 252 SDef
Calm Nature (+SDef, -Atk)
- Shadow Ball
- Flamethrower
- Energy Ball
- Pain Split
>This out classes Shedinja.Lampent is a great Spinner Stopper.So when you set up entry hazards and you predict a Poke is going to try and use Rapid Spin send him out.Shadow Ball and Flamethrower are your two lovely Stabs. Energy Ball is coverage and Covers your rock and ground weakness and Pain Split it for when you need your HP balanced out.
Enjoy Your Team.
Importable Copy if wanted.
Bastiodon (M) @ Leftovers
Trait: Sturdy
EVs: 252 HP / 4 Def / 252 SDef
Impish Nature (+Def, -SAtk)
- Iron Head
- Stealth Rock
- Toxic
- Roar
Creppy. (Ariados) (F) @ Black Sludge
Trait: Insomnia
EVs: 4 HP / 252 Atk / 252 Spd
Adamant Nature (+Atk, -SAtk)
- Poison Jab
- Sucker Punch
- Toxic Spikes
- Protect
Seaking (M) @ Life Orb
Trait: Lightningrod
EVs: 252 Atk / 92 SAtk / 164 Spd
Lonely Nature (+Atk, -Def)
- Waterfall
- Ice Beam
- Megahorn
- Return
2Bright? (Leafeon) (F) @ Leftovers
Trait: Chlorophyll
EVs: 4 HP / 252 Atk / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Leaf Blade
- X-Scissor
- Aerial Ace
- Swords Dance
Masquerain (M) @ Life Orb
Trait: Intimidate
EVs: 4 HP / 252 SAtk / 252 Spd
Modest Nature (+SAtk, -Atk)
- Bug Buzz
- Air Slash
- Hydro Pump
- Quiver Dance
Lampent (M) @ Eviolite
Trait: Flame Body
EVs: 252 HP / 4 Def / 252 SDef
Calm Nature (+SDef, -Atk)
- Shadow Ball
- Flamethrower
- Energy Ball
- Pain Split