Yea, there's one on the net
The demo only gives you 3 classes to play with (i think)...once you hit level 8, you get to chose a second mastery skill...which gives you your final class

which is a pretty nice way of doing it.
My character is a warfare/spirit master..giving her a class of Spellbreaker - i've got another one which is warfare/rouge which gives her an Assassin class (yes, i have female characters...)