5th Gen Team Advice

[MKT585]

Sup' folks. I'm doing another playthrough of White 2. I needed advice on the next member I should add to my team. I don't have access to trading keep in mind. And no legendaries please.
My current team is
Umbreon Lvl 42
Bite
Moonlight
Return
Quick Attack

Lucario Lvl 41
Copycat
Swords Dance
Force Palm
Bone Rush

Braviary Lvl 41
Slash
Air Slash
Hone Claws
Fly

Darmanitan Lvl 42
Fire Punch
Flare Blitz
Hammer Arm
Headbutt

Starmie Lvl 34 (fresh catch)
Surf
Swift
Confuse Ray
Recover

I'm at Undella town. Can you guys sorta rate my team. And give advice for another Pokémon that would do well with them. Thanks in advance.

 

[Ho-Oh]

I'll leave the move rating to someone else but for Pokemon suggestions:

Hmmm... maybe a special Grass type? You have a lot of physical attackers... I assume you didn't start with/still have a Snivy? I think Amoonguss would be a cute fit actually. Route 13 can help you out with a Foongus Hidden Grotto :) Catch one with the Hidden ability there and you have a really useful Pokemon that can definitely be helpful!