Jade Empire in Style is a mod for the original game, that makes pretty much all of the game's styles available to players and adds a few more to boot. You can learn all of these new styles by fighting enemies who use them. Whether you do or do not get the chance to learn in combat, depends mostly on the amount of damage you allow your enemies to do to you. Some styles may be harder to acquire than others, because they're used by tough opponents, but by and large you should be able to acquire quite a few styles more than in vanilla Jade Empire.