Subclass/Dual Class Master Raina:

Sorry, but you're not qualified to add a subclass. To add a new subclass, you need the following qualifications:
First, you've completed the 'Red Thread of Fate' quest. If you want to get on that, let me know.
Second, your current class has done the 2nd class transfer, and all your subclass levels are 75 or higher. For example, if your subclasses are Temple Knight and Silver Ranger, they must both be level 75 for you to add a third subclass.
Third, you may only have up to 3 subclasses, I'm afraid.
Got it?