Oh no!

[latios Z]

Ack!Why!I battled Hall matron argenta two times!But I still the loser!The first time she had a starmie that fooled me with hydro pumps and at the second time she had a latios[one of my favorites]!Can anyone give me some advice about how I can defeat the hall matron?[I select gyarados];107;

 

[SHINY CATCHER]

There isn't very many different ways to explain how to get through as the Pokemon are random but my advice is.
1.Get a Pokemon with a wide movepool
2.Teach it 4 different type moves
3.Give it a choice item
Thats how me and my Gallade got through to get our coloured pass.

 

[Esmerry]

Yep, you should get a Pokémon with moves that can defeat a lot of types, like this:

Ice move/Grass move/Water move/Fire move are your Pokémons moves

An ice move defeats Flying/Grass/Dragon etc.
An grass move defeats Water/Ground/Rock? etc.
A water move defeats Fire/Ground/Rock etc.
A fire move defeats Grass/Bug and so on.

 

[latios Z]

Hmm...My gyarados is lv. 83 and he knows:Ice beam,hydro pump,blizzard and waterfall.Isn't it good anyway?

 

[Tiomasta]

Hmm...My gyarados is lv. 83 and he knows:Ice beam,hydro pump,blizzard and waterfall.Isn't it good anyway?

I don't want to seem rude, but hell no, that's horrible.

Gyarados has a great base Atk but a very bad Sp.Atk, so only teach it physical moves(the only physical one there is Waterfall).
Also, in most situations, you should not have two damaging moves of the same type, and that moveset only has two types.
Also, you do not have a move against Shedinja, which you should have if you're in the Frontier.

You're trying to use that Gyarados in the Hall, maybe you should consider a set something like this?

Gyarados @ Choice Band/Focus Sash
Adamant/Jolly, 252 Atk, 252 Speed, 4 HP
-Waterfall
-Earthquake
-Ice Fang
-Bite

I don't think it gets walled by anything in the Hall, and Bite is there for Shedinja. Also is better than Waterfall if the opponent is weak to Dark. Same power, but Bite has more chance to flinch.

Ah, yes, Focus Sash is if you want to fight Electric-types.

 

[swampertlover5712]

gyarados can learn aqua tail as well...
but try going with a pokemon that has very little to no weakness.
has good, balanced stats, and has a wide move set.

 

[hello moto]

Try with Electivire

Electivire@Expert belt
Adamant/Jolly
EV- 252 Atk, 252 spd, 4 HP

-Earthquake
-Thunder punch
-Ice punch
-Cross shop

It has a wide move pool and covers 13 out of the 17 types of pokemon, though it is useless against a Shedinja, if your doing bug, just go to the move tutor and teach it Fire punch.
I personally use this and Gyrados (like the one Tiomasta has suggested), they work well against the hall.
Gyarados will probably work better as you don't have to change its movepool (easier to manage), but Electivire only has one weakness which is Ground.

 

[A7X_Slayer]

Try these....

these pokes worked for
Charizard
Solarbeam
Arial Ace
Fire blast
Focus blast

Latias
Recover
Dragon pulse
Fly
Psychic

Salamence
Thunder fang
Fire fang
Dragon claw
Fly

Electivire
Thunder punch
Fire punch
Cross-Chop
Giga impact

see all the move types are different allowing you to attack a variety of types

hoped i helped

 

[Calm PokeMaster]

Any Pokemon (must be EV trained) with a wide movepool should be able to beat the Hall Matron.....

 

[latios Z]

Oh...Okay...Well you may be lucky.You have another region's pokemon too...The truth is...RAIKOU.I think that raikou can do very well.Don't you think so?But I won't give up!What do you say about milotic?Will it win the Hall Matron Argenta?

 

[foxyman1167]

1. Don't use Pokemon with double weakness'
2. Use a pokemon that can hit Shedinja.
3. Use items appropriate to each type.

 

[latios Z]

What do you mean!Milotic is quite strong!But,okay!I don't have any!!!About giratina?What happens with giratina????

 

[Tiomasta]

Giratina, along with some other legendaries, is banned from the Frontier.

I don't think anything can be better than Slaking for winning the Hall.

Slaking "Hallslayer" @ Choice Band
Adamant, 252 Atk, 252 Speed, 4 HP
-Giga Impact
-Earthquake
-Fire Punch
-Sucker Punch

Something like that.
The strategy is simple. Look what pokemon you're up against and OHKO it.

If you're against a Ghost, Sucker Punch it.
If you're against something which doesn't resists Normal, Giga Impact.
If you're against a Rock or a Steel, Earthquake, unless that Steel is Scizor, Forretress or Bronzong.
If you're against Scizor, Forretress, Bronzong or Shedinja, Fire Punch.

Coverage is great(I don't think there is one poke that doesn't take much damage from this moveset), and Choice Banded Adamant Slaking with those moves has enough power to OHKO most enemies you see.

 

[latios Z]

You're right...That's not <<a piece of cake>>,it seems...[I will take some wi-fi battles and...trades when I see a cool one].What's about mew???She can take place at frontier or she is banned too?

 

[Tiomasta]

Nah, Mew is banned too.
The pokes banned from the Frontier are:

Mewtwo, Mew.
Lugia, Ho-oh, Celebi.
Kyogre, Groudon, Rayquaza, Jirachi, Deoxys.
Dialga, Palkia, Giratina, Phione(what?), Manaphy, Darkrai, Shaymin(both formes) and Arceus.

 

[Barrabás]

Giratina, along with some other legendaries, is banned from the Frontier.

I don't think anything can be better than Slaking for winning the Hall.

Slaking "Hallslayer" @ Choice Band
Adamant, 252 Atk, 252 Speed, 4 HP
-Giga Impact
-Earthquake
-Fire Punch
-Sucker Punch

Something like that.
The strategy is simple. Look what pokemon you're up against and OHKO it.

If you're against a Ghost, Sucker Punch it.
If you're against something which doesn't resists Normal, Giga Impact.
If you're against a Rock or a Steel, Earthquake, unless that Steel is Scizor, Forretress or Bronzong.
If you're against Scizor, Forretress, Bronzong or Shedinja, Fire Punch.

Coverage is great(I don't think there is one poke that doesn't take much damage from this moveset), and Choice Banded Adamant Slaking with those moves has enough power to OHKO most enemies you see.

All Fighting-type Pokemon with Fake Out - Infernape, Hitmontop, et al - will eat Hallslayer alive.

I know they did mine

 

[swampertlover5712]

try heatran, he isn't banned from the Battle Frontier.
just watch out for ground-type moves...

 

[fireperson]

You should try using a pokemon that has little or no weaknesses,and has at least 3 different types of moves.I used my lucario with shadow ball,dragon pulse,aura sphere and drain punch. When she sent out a Hippowdon,I was worried alot but I still won somehow.

 

[Tiomasta]

All Fighting-type Pokemon with Fake Out - Infernape, Hitmontop, et al - will eat Hallslayer alive.

I know they did mine

Hm, yeah, Fake Out...
I will try to take out all Fighting-types before anything else, then. Fire-types next.
If you keep trying, then surely they will eventually not use Fake Out or keep sending pokes without Fake Out, or just not KO you.

With this in mind, I will try later a Sashed Fake Out Weavile.

try heatran, he isn't banned from the Battle Frontier.
just watch out for ground-type moves...

I assume we're talking about pokes who can win at the Hall(that is, get the gold print, and that is, fight every type 10 times, plus the Brain twice), so no "watch out for type X".