The Leftover Mastery Book

Hello, [ชื่อ]. Do you happen to be a person who wasn't able to receive the Dual Blade Event Mastery Book that was given out during the 2010 Winter Event? For people just like you, we've decided to pass out the Mastery Books once again. Would you like to receive it now?

Please continue working hard until you reach a level where you can use the Mastery Book!

Do you not need a Mastery Book? I really doubt that...

Keep leveling up until you can use the Mastery Book!