Nothing says happy birthday like a a new player class. Tera is celebration for their second year anniversary with double XP and the introduction of the Reaper.
The Reaper is an incredible strong close-ranged DPSer that you can unlock when you have a character level 40 or higher. Just make sure you have an addition character slot.
The Reaper will be available for Tera players on May 13th. You just have to own a copy of Tera.