Mastering Skills

There are a lot of games out there where your character starts out rather weak, and as you progress through the game, you are rewarded with stronger attacks and skills.  The idea is "from all the training, you got more powerful".  Let's face it though, you didn't hone your skills any better, the game just gave you rewards. 

Are there any games out there that "reward" you with skills that YOU have to master?  I'm thinking skills that, though they allow your character to do cooler and more powerful attacks, require actual skill on the player's part to effectively use, or, if used ineffectively, make the game harder?  I'm thinking skills like speed boosts that make your character harder to control.  I guess you could say that items and skills that increase your attack power, but lower your defense work this way.  Any other ideas for similar things that should be in a game, or you've seen in a game?

Yeah, I was thinking more of the action or action rpg genre.  Games like the newer Castlevania games, for example, you start off weak, but end up godlike from all the better weapons and stuff.  I just think it would be interesting to, for a change, only give the player things that they have to themselves master using.