Pros: The best dash ability out of all adventurers. Trap sense. Great attack speed. Incredible skills.
Cons: Painfully shortened attack range. Starts off at low health.
Charme is my girl. My main. Fast, deadly, and ready for any situation. Once I got her, Louie took a permanent backseat in my party. Her dash makes the chore of walking through large dungeon floors feel like nothing.
Her skills? God like. Her first skill is the only one you need really. Shadow clones. You can summon five at max. If you can arrange them properly (as they appear in whatever direction you're facing when you use the skill), you can surround any boss and send them to their deaths in a matter of seconds. Her flame tackle is great for getting out of dicey situations. Her final skill, the spider net trap I use the least, but it most certainly has its uses. Especially during the coliseum boss battles.
But her short attack range is something you're going to have to get used to. Be prepared to get hurt, a lot, in the process. I find that you tend to get reckless with Charme. Dashing around wildly through a dungeon floor can easily land you in trouble. Trying to approach your enemies from the front, then misjudging the range of her dagger and the enemy, and missing only to get a face full of tentacle? A painful experience I've gone through time and time again with her.
Equip her with the best gear you can, pay attention to what you're doing, and you don't need any other character really.