HP washing and dual blades....

Starting at level 30 makes you loose 500 or so hp and 100-200 mp, because nexon did not include the advancement bonuses. So it happens that dual blade's min mp is higher than a regular thief, but since you dont have the extra from the advancements, you cannot take out of mp. Same with hp actually. you're below the min and that's why it is grayed out too.

See this thread: http://www.southperry.net/showthread.php?t=29511