Each class base has a Class Master. A Class Master is an NPC that gives you the options to cash in your class contribution. You can exchange them for a random item, a title, or buy a formula.
Assassin: Assasin Plum (92,46) - Assasin
Beggars Alliance: Elder Cheng (91,100) - Beggars Alliance
Lotus Order: Grandma Li (96,51) - Mt. Emei
Minstrel: Minstrel Su (125,146) - Minstrel Cave
Pyromancer: Master Lin (98,52) - Fire Palace
Royalty: Benevolent (95,67) - Royal Temple
Shaolin: Silence (91,72) - Shaolin Temple
Taoist: Master Zhang (78,86) Mt. Wu Tang
Voodoo: Voodoo Han (95,75) - Voodoo Sea