I've seen a lot of methods that RPGs employ to determine how the characters in the player's party learn new abilities. They're quite numerous, really...sometimes characters just learn new moves when they level up, sometimes there are separate experience points devoted to leveling up special attacks, some games have spots on a grid of sorts that you can activate to learn new powers, and plenty of games actually just sell the new skills in stores. Plenty of times, 1 or 2 abilities are only learned from certain quests or completing specific plot events. One of the ideas that I actually really liked (for reasons I can't quite explain) was Final Fantasy 9's system of having most abilities learned from going through enough battles while wearing a certain piece of equipment.* Sometimes these ways of having characters learn new talents is creative (spell creation in Treasure of the Rudras, Plume usage in Valkyrie Profile: Covenant of the Plume), and sometimes it's not (level-up learning in Dragon Age 1, Tech Points in Chrono Trigger), just as it sometimes provides a game with balance and provides diverse battle roles for characters (pre-established Sphere Grid areas in Final Fantasy 10, ability slot limitations in any given Shin Megami Tensei title), and sometimes is unbalanced and stupidly just makes every character in the game interchangeable (Materia in Final Fantasy 7, Job Classes in Final Fantasy 5). But despite a fairly strong variety in how games handle the process of gaining abilities, it's a rare occasion when I find a system that I really can't stand.
Wild Arms 2, however, is that rare occasion. Or rather, the character Kanon is. In WA2, most every character has their own unique way of gaining abilities. Plot events provide a few for everyone, Brad and Ashley get the rest of theirs from finding certain items, Lilka goes to a shop for hers, Marivel gets her abilities by draining them from the right enemies, and Tim adds to his move set when he kills enemies with a certain summon monster equipped. Some of these are more time-consuming and annoying than others (Tim and Marivel), but they're all pretty functional and basic methods. Kanon, however...basically, she gains new abilities when she uses her current ones.
Now, at first glance, this COULD be functional, if it were measured in constants. What I mean is, if the system was set up where Kanon would get, say, Super Slash 2 after using the ability Super Slash 1 a certain amount of times, then this would be fine. You could count out how many more uses you would need until you gained her next move. Simple. A little time-consuming no doubt, but simple.
But it's not constant. It's random. Any time you use Super Slash 1, there's a certain percent chance that Kanon will learn Super Slash 2 after using it. This is not such a big deal with the first of her abilities to learn, since they've got chances of 1/4 and 1/12, which are pretty good--a few uses and you'll probably get the next abilities fast enough. But her best abilities, Phalanx and Eagle Claw? The chance that you'll learn them from using her abilities are, at any given use, 1/48 and 1/96, respectively. One out of NINETY-SIX. That means that out of 96 uses of Phalanx, you can only reasonably expect 1 of them to result in Kanon learning her final ability.
That by itself is totally unreasonable, of course, particularly since there's actually no guarantee that you won't be exceptionally unlucky and still not have gotten Eagle Claw after 96 tries. But, my friends, the terrible nature of this process does not end there. One must also consider the circumstances necessary to use the high-powered attacks that you need to in order to potentially activate Kanon's Eagle Claw. You see, in Wild Arms 2, there is not MP, persay--there are Force Points. You basically start every battle with a Force Point total equaling your character's level, and the way to get more during battle are:
Get hit by an attack
Use a very rare FP restoration item
Use 1 certain summoned monster's ability
So to raise your FP, you're going to be, one way or another, involved in a battle that takes multiple turns. And the cost for the ability Phalanx, which you need to use to get Eagle Claw, is...90 FP. This means that until Kanon has reached level 90, which is something like 35 levels higher than you need to be to comfortably beat the entire game, you have to be in combat for at least a couple turns to use Phalanx at all. What does that mean? It means that if you want to pursue Eagle Claw during normal enemy encounters, you're going to have to increase the amount of time you spend in random battles by at least twice. And with that comes the consideration that normal enemies are only going to take one hit from Phalanx before dying, as it's rather powerful, you're going to be increasing the time you fight normal enemies by at least 100% just for the opportunity to try for the new ability 3 times or so. That SUCKS.
The other option you can take is to use the only battles that you'll normally get Kanon 90 FP in due to their length--boss battles--to spam the move over and over. This is almost as annoying, though, because if you're just hitting the boss with one move every turn, you're still increasing the amount of time you're spending in monotonous RPG combat, and if you're using any attacks more than Phalanx, the boss dies too quickly for Kanon to have used the move often enough to have any chance of learning the damn Eagle Claw ability.
In my replay of WA2 a few months ago, I did both methods--the only attack I used against bosses was Phalanx, and I increased the length of several normal enemy encounters so that I could have Kanon fire off Phalanx a couple times (and I'd just like to note, in case it's been forgotten, that just getting the Phalanx ability is an annoying, random, time-consuming process in itself!). You know when I finally learned the goddamn Eagle Claw ability? Second to last dungeon. That's, what, a THIRD of the game that you can spend waiting for this damn ability to show up, hindering your progress the entire time?
And yes, I do realize that I could have just stopped with Phalanx and (apparently) gotten through the game just fine with it alone. Not only do I realize that, I heartily recommend it--hell, I think Phalanx by itself is too much of a pain in the ass to learn for Kanon, so anyone planning to play the game, just stick to the other abilities she can learn. But whether a player CAN make do with a less-effective work-around is not the point--the point is that the player should not HAVE to avoid this tedious idiocy.
* Final Fantasy 6 actually had this idea first, but it was tragically underused, almost completely eclipsed by the far less interesting Magicite system of learning magic, which ruined most of the game's characters' battle individuality.