How can I beat Iris's Pokemon in Pokemon Black and White 2?

Question

I can't beat Iris's Pokemon.

Team
Lvl 66 Emboar Female
Item Lucky Egg
Timid Nature

Moves
Heat Crash
Flame Charge
Arm Thrust
Will-O-Wisp

Lvl 56 Ampharos female
Lax nature
Item Rocky Helmet

Moves
Strength
Electro Ball
ThunderPunch
Thunderbolt

Lvl 38 Skarmory Male
Serious nature
Item Exp. Share
Moves
X-Scissor
Cut
Metal Sound
Steel Wing

Lvl 41 Beartic Female
Bold Nature
Item

Moves
Slash
Frost Breath
Brine
Endure

Lvl 46 Crobat Female
Relaxed nature

Moves
Wing Attack
Poison Fang
Acrobatics
Bite

Lvl 48 Flygon Female
Hardy Nature

Moves
Struggle Bug
Dragon Tail
Earth Power
Fly

Comments

Train to lvl 100, easy

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The rest of your team is far too underlevelled. Get everyone else up to your Emboar's level and you should be fine.

Answer 1

Most of your team is underlevelled as fondant said, travel to victory road and travel to where the double grass is and train there and fight any trainers you might have missed while swaping around your Emboar's lucky egg to the Pokémon your training until the rest of your team is in the low/mid 50's or higher.

Answer 2

You have under-leveled Pokemon!

Ok. Champion Iris is usually easy to beat, IF your Pokemon are around the same level as hers.

Basically all you need to do is level up your Pokemon. Victory Road is the right place to do that.

After your Pokemon are at least lv 50 you can go ahead and try it again.

As for her team, I think Hydreigon is the main threat.

It knows:
Flamethrower (Fire)
Charge Beam (Electric)
Dragon Pulse (Dragon)
Surf (Water)

So you can't go again's it with Emboar or Beartic. I would usually go for a single fighting type Pokemon, but since you don't have that, I think Ampharos is your best bet here. It's the only Pokemon Hydreigon isn't super effective against in your team.
Her other Pokemon shouldn't be a problem.

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EDIT: You also have a very unbalanced team. You have 2 flying type Pokemon + Flygon which can learn Fly. There isn't much you can do about it at this point of the game, but keep in mind that a good team consists in having different types of Pokemon.