Leveling up is only the beginning. You can make your main character stronger through a system of subclasses. A character can have three subclasses in total.
On level 85 you can complete Red Thread of Fate quest from Raina in the Talking Island Village and get the option to add a subclass.
Ertheia can't have subclasses or learn subclass skills. They are able to add only Dualclass after completion of Winds of Fate - Encroaching Shadows quest.
When you’ve completed Red Thread of Fate quest, talk to Raina located in the Talking Island Village, to choose a subclass.
Raina can also help you delete, change a subclass or change your current subclass while keeping the same level with item Subclass Change Certificate.
To learn subclass skill you must get a subclass to 65, 70, 75 and 80. Talk to Trandon in the Talking Island Village and ask to be certified on that subclass which will reward you with Certificate - Subclass. A total of 12 certificates can be obtained. Subclass skills can be reset for
10,000,000 Adena. Subclass and Dualclass all benefit from subclass skills.