A lesser used, but still very potent move is Charm. This moves reduces a single Pokemon's attack by two stages, halving any physical damage. While this move is very useful, it compares to a very similar move, Will-O-Wisp. Will-O-Wisp is a move that inflicts the Burn status on a single target, which also reduces the Attack by half.
Generally, of the two moves used, if you have the option, people would choose Will-O-Wisp. In fact, it is generally that case that Charm is almost never used, perhaps seen as a gimmick move that, since its effects are temporary until you switch, is less useful overall than WoW. However, there are situations, where Charm is more useful than Will-O-Wisp, and this brings us to the topic of discussion.
Also, the move Featherdance accomplishes the same thing as Charm, so it can also be included here too. From now on, I will refer to Charm as including Featherdance users, this increases the number of Pokemon that can use a Charm effect.
Who learns Charm
Pokemon XD: Gale of Darkness greatly expanded the number of Pokemon that can learn Charm, and I will present a list here:
Venusaur
Nidoqueen
Pikachu
Raichu
Vileplume
Clefable
Persian
Wigglytuff
Rapidash
Flareon
Jolteon
Vaporeon
Snorlax
Furret
Togekiss
Granbull
Ursaring
Umbreon
Espeon
Bellossom
Donphan
Blissey
Linoone
Gardevior
Azumarill
Delcatty
Minun
Illumise
Breloom
Wobbuffet
Mr Mime
Luvdisc
Latias
Pachirisu
Lopunny
Purugly
Lumineon
Leafeon
Glaceon
Mesprit
Manaphy
Ninetales (XD)
Dugtrio (XD)
Golduck (XD)
Arcanine (XD)
Mamoswine (XD)
Houndoom (XD)
Camerupt (XD)
Walrein (XD)
As you can see, there are a large number of Pokemon that can learn Charm in various ways. I pointed out the XD ones simply because they may have a few egg move incompatibilities.
Featherdance can also be used in place of Charm, and the number of Pokemon that can use it are:
Pidgeot
Farfetch'd
Noctowl
Natu
Lugia
Altaria
Staraptor
Chatot
Honchkrow
Who learns Will-O-Wisp
Ninetales
Banette
Dusknoir
Charizard
Arcanine
Rapidash
Gengar
Weezing
Magmortar
Flareon
Moltres
Mewtwo
Mew
Typhlosion
Mismagius
Magcargo
Houndoom
Entei
Ho-oh
Blaziken
Shedinja
Sableye
Camerupt
Torkoal
Solrock
Absol
Infernape
Drifblim
Spiritomb
Rotom
Heatran
Giratina
Darkrai
Arceus
As you can see, herein lies Will-O-Wisp's first problem, since only certain types learn it (mostly Ghost and Fire, with a few rare exceptions like Solrock) and most people are familiar with WoW users, it can be predicted and prevented. Also, Charm has many more users than WoW.
What can Charm do that Will-O-Wisp cannot?
This is the important question. I'm using this thread to concentrate on the benefits of Charm, so I will be highlighting those here, since you should all be familiar with Will-O-Wisp's uses and benefits. I'll try and bring it under a few simple points:
1) Temporary changes force switches.
This is important to remember, with most (if not all) teams making use of the entry hazard moves, Stealth Rock, Spikes and Toxic Spikes. Since Charm is a temporary effect, people will seek to remove it at the earliest opportunity, which is usually achieved by switching out. Forcing more switches means your team gets more benefit out of the entry hazards, and puts more pressure on the opposing team as their effects stack up.
2) It is unexpected
Will-O-Wisp users, as we are aware, are commonly known. However, I'll bet before looking at that list above, most of you couldn't name more than, say half a dozen Charm users. Because it can be such a surprising move, it can catch a lot of opponents off guard and put you ahead. This is basic surprise factor at its finest, but like a lot of surprises can be lethal to your opponent if they don't know it is coming.
3) There are less counters to Charm
There are plenty of known ways to stop Will-O-Wisp. For one, it cannot affect a Fire type, in fact it can activate Flash Fire on the few Pokemon that do have it. Charm not only works on Fire types, but it doesn't give your opponent an advantage further down the line by boosting his Fire moves.
Charm can work on something that already has a status (including Burn), which means you can, for example, reduce the speed by paralysing and the attack with Charm. In WoW vs Thunder Wave's case, you can only do one or the other.
Guts users may predict a burn and switch into WoW, putting you at a disadvantage as they suddenly gain a 50% boost in Att from the trait. However, Guts users can be still affected by Charm, and they do not get a bonus from switching into it, expecting the trait to boost their Attack, in fact Charm is all negative for Guts users, something WoW cannot accomplish. Of course, many Guts users carry a Toxic or Flame Orb, but after one use of Charm even they will have less Attack than when they started - 150/2 = 75% damage after one Charm use).
If people have a choice, they will forego Hyper Cutter in favour of a different ability. Mold Breaker Pinsir, Sand Veil Gliscor, for example, are both used over Hyper Cutter Pokemon of the same type. Hyper Cutter users are less common, with perhaps being a good exception are among Baton Pass teams or recipients of Baton Pass chains.
Clear Body of course, is not a common trait but it seen on a lot of Pokemon in OU, including Metagross, Tentacruel, and the Regi trio. However, three of these are weak to Fire, and almost all are weak to Ground, so Charm in conjunction with Earthquake or Earth Power can cover this problem. Regice and Tentacruel do not mind having their Attack reduced anyway, neither does the rare special Metagross, if you can somehow find a way around their trait (Skill Swap/Gastro Acid?)
The move Mist prevents stat losses for 5 turns, and can be used to prevent Charm from working. This is a never-used move, but it is included for completeness, since it is technically a Charm counter. If the opponent is holding a White Herb, it can prevent the use of Charm once.
While burn can be removed, by using Heal Bell, Rest, Aromatherapy and so on, even with traits like Shed Skin, Charm cannot be removed without switching, unless using the move Haze. Charm also has the move advantage over Curse, Howl and Dragon Dance, since it overpowers these +1 Attack moves with a -2 effect, making it win out in the long term.
4) It can be used more than once
Will-O-Wisp causes normal Burn, which is half damage. One of the advantages of Charm, is that it can be used more than once if the Attack reduction isn't low enough to cause the opponent a problem (although in the majority of physical attacker's cases it will be enough to only need to use Charm once). If you need to protect another Pokemon on your team, perhaps reducing the Attack further to -4 or even -6 can either force a switch, or if that is not possible, making it harmless enough that you can bring something else in. Charm is better than Memento too, in that you don't need to sacrifice a Pokemon in order to use it, it can be used multiple times during a match by the same Pokemon, giving it more versatility.
5) More reliable move.
Will-O-Wisp is a move with 15 base PP, max of 24, and an accuracy of 75%. This means it can and will miss, sometimes being crucial for the match. Charm however has 20 base PP, max of 32 and an accuracy of 100%. This means it will always affect the opponent (unless immune from Hyper Cutter/Clear Body), unlike WoW which can miss, and has more PP so can be used more often in the case of a long drawn out match. Swords Dance has 30 base PP, 48 max, so in the case of Charm vs Swords Dance, SD will win out, but this is also the case with SD vs WoW anyway.
So, which is better - Charm or Will-O-Wisp? Clearly, its hard to call, given both moves have advantages and disadvantages that one can cover where as the other might not. The temporary nature of Charm may not be appealing to some, but the fact that it is more reliable and affects a wider variety of opposing Pokemon, as well as having a larger list of users, give it more versatility. I'm on the fence, as I can see the use of Charm as well as WoW, but what do you all think?
Generally, of the two moves used, if you have the option, people would choose Will-O-Wisp. In fact, it is generally that case that Charm is almost never used, perhaps seen as a gimmick move that, since its effects are temporary until you switch, is less useful overall than WoW. However, there are situations, where Charm is more useful than Will-O-Wisp, and this brings us to the topic of discussion.
Also, the move Featherdance accomplishes the same thing as Charm, so it can also be included here too. From now on, I will refer to Charm as including Featherdance users, this increases the number of Pokemon that can use a Charm effect.
Who learns Charm
Pokemon XD: Gale of Darkness greatly expanded the number of Pokemon that can learn Charm, and I will present a list here:
Venusaur
Nidoqueen
Pikachu
Raichu
Vileplume
Clefable
Persian
Wigglytuff
Rapidash
Flareon
Jolteon
Vaporeon
Snorlax
Furret
Togekiss
Granbull
Ursaring
Umbreon
Espeon
Bellossom
Donphan
Blissey
Linoone
Gardevior
Azumarill
Delcatty
Minun
Illumise
Breloom
Wobbuffet
Mr Mime
Luvdisc
Latias
Pachirisu
Lopunny
Purugly
Lumineon
Leafeon
Glaceon
Mesprit
Manaphy
Ninetales (XD)
Dugtrio (XD)
Golduck (XD)
Arcanine (XD)
Mamoswine (XD)
Houndoom (XD)
Camerupt (XD)
Walrein (XD)
As you can see, there are a large number of Pokemon that can learn Charm in various ways. I pointed out the XD ones simply because they may have a few egg move incompatibilities.
Featherdance can also be used in place of Charm, and the number of Pokemon that can use it are:
Pidgeot
Farfetch'd
Noctowl
Natu
Lugia
Altaria
Staraptor
Chatot
Honchkrow
Who learns Will-O-Wisp
Ninetales
Banette
Dusknoir
Charizard
Arcanine
Rapidash
Gengar
Weezing
Magmortar
Flareon
Moltres
Mewtwo
Mew
Typhlosion
Mismagius
Magcargo
Houndoom
Entei
Ho-oh
Blaziken
Shedinja
Sableye
Camerupt
Torkoal
Solrock
Absol
Infernape
Drifblim
Spiritomb
Rotom
Heatran
Giratina
Darkrai
Arceus
As you can see, herein lies Will-O-Wisp's first problem, since only certain types learn it (mostly Ghost and Fire, with a few rare exceptions like Solrock) and most people are familiar with WoW users, it can be predicted and prevented. Also, Charm has many more users than WoW.
What can Charm do that Will-O-Wisp cannot?
This is the important question. I'm using this thread to concentrate on the benefits of Charm, so I will be highlighting those here, since you should all be familiar with Will-O-Wisp's uses and benefits. I'll try and bring it under a few simple points:
1) Temporary changes force switches.
This is important to remember, with most (if not all) teams making use of the entry hazard moves, Stealth Rock, Spikes and Toxic Spikes. Since Charm is a temporary effect, people will seek to remove it at the earliest opportunity, which is usually achieved by switching out. Forcing more switches means your team gets more benefit out of the entry hazards, and puts more pressure on the opposing team as their effects stack up.
2) It is unexpected
Will-O-Wisp users, as we are aware, are commonly known. However, I'll bet before looking at that list above, most of you couldn't name more than, say half a dozen Charm users. Because it can be such a surprising move, it can catch a lot of opponents off guard and put you ahead. This is basic surprise factor at its finest, but like a lot of surprises can be lethal to your opponent if they don't know it is coming.
3) There are less counters to Charm
There are plenty of known ways to stop Will-O-Wisp. For one, it cannot affect a Fire type, in fact it can activate Flash Fire on the few Pokemon that do have it. Charm not only works on Fire types, but it doesn't give your opponent an advantage further down the line by boosting his Fire moves.
Charm can work on something that already has a status (including Burn), which means you can, for example, reduce the speed by paralysing and the attack with Charm. In WoW vs Thunder Wave's case, you can only do one or the other.
Guts users may predict a burn and switch into WoW, putting you at a disadvantage as they suddenly gain a 50% boost in Att from the trait. However, Guts users can be still affected by Charm, and they do not get a bonus from switching into it, expecting the trait to boost their Attack, in fact Charm is all negative for Guts users, something WoW cannot accomplish. Of course, many Guts users carry a Toxic or Flame Orb, but after one use of Charm even they will have less Attack than when they started - 150/2 = 75% damage after one Charm use).
If people have a choice, they will forego Hyper Cutter in favour of a different ability. Mold Breaker Pinsir, Sand Veil Gliscor, for example, are both used over Hyper Cutter Pokemon of the same type. Hyper Cutter users are less common, with perhaps being a good exception are among Baton Pass teams or recipients of Baton Pass chains.
Clear Body of course, is not a common trait but it seen on a lot of Pokemon in OU, including Metagross, Tentacruel, and the Regi trio. However, three of these are weak to Fire, and almost all are weak to Ground, so Charm in conjunction with Earthquake or Earth Power can cover this problem. Regice and Tentacruel do not mind having their Attack reduced anyway, neither does the rare special Metagross, if you can somehow find a way around their trait (Skill Swap/Gastro Acid?)
The move Mist prevents stat losses for 5 turns, and can be used to prevent Charm from working. This is a never-used move, but it is included for completeness, since it is technically a Charm counter. If the opponent is holding a White Herb, it can prevent the use of Charm once.
While burn can be removed, by using Heal Bell, Rest, Aromatherapy and so on, even with traits like Shed Skin, Charm cannot be removed without switching, unless using the move Haze. Charm also has the move advantage over Curse, Howl and Dragon Dance, since it overpowers these +1 Attack moves with a -2 effect, making it win out in the long term.
4) It can be used more than once
Will-O-Wisp causes normal Burn, which is half damage. One of the advantages of Charm, is that it can be used more than once if the Attack reduction isn't low enough to cause the opponent a problem (although in the majority of physical attacker's cases it will be enough to only need to use Charm once). If you need to protect another Pokemon on your team, perhaps reducing the Attack further to -4 or even -6 can either force a switch, or if that is not possible, making it harmless enough that you can bring something else in. Charm is better than Memento too, in that you don't need to sacrifice a Pokemon in order to use it, it can be used multiple times during a match by the same Pokemon, giving it more versatility.
5) More reliable move.
Will-O-Wisp is a move with 15 base PP, max of 24, and an accuracy of 75%. This means it can and will miss, sometimes being crucial for the match. Charm however has 20 base PP, max of 32 and an accuracy of 100%. This means it will always affect the opponent (unless immune from Hyper Cutter/Clear Body), unlike WoW which can miss, and has more PP so can be used more often in the case of a long drawn out match. Swords Dance has 30 base PP, 48 max, so in the case of Charm vs Swords Dance, SD will win out, but this is also the case with SD vs WoW anyway.
So, which is better - Charm or Will-O-Wisp? Clearly, its hard to call, given both moves have advantages and disadvantages that one can cover where as the other might not. The temporary nature of Charm may not be appealing to some, but the fact that it is more reliable and affects a wider variety of opposing Pokemon, as well as having a larger list of users, give it more versatility. I'm on the fence, as I can see the use of Charm as well as WoW, but what do you all think?