I've been playing Blade and Soul a lot (KR/CN beta and now the NA beta), and one thing I find that's interesting is that each *skill* has it's own talent/skill tree. You can change/alter how the skill works. Like for Force master (mage type) a fireball can either do more damage, or aoe burst damage, then further down the tree it may add a burning effect, or a debuff and depending on what you want to do with your class, you can build it a certain way based on your playstyle (whether it's pvp, aoe, direct damage, or control, etc). of course there's optimal builds as there will be with any form of skill/talent tree, but it still gives a fair amount of customization and play style differences.