This Special Title can be acquired after defeating at least 70 Legion Raid Boss dragons as part of a subclass-changing quest initiated in the pyramid of the hero king, Pharaoh Takel, who slew a dragon using a divine sword. It was added in the 2008 expansion pack, Supreme Ruler's Ambition, but the Subclass remained largely unknown due to the difficulty in clearing its prerequisite. After the next expansion pack, which raised the level cap to 80, more people were able to acquire it.
Like any subclass derived from the Hunter subclass, however, Dragon Slayer has the downside of losing any and all production skills and does not gain any bonuses in drop rate like the Hunter subclass has. In this way, it's considered a downgrade from Hunter, and most people choose not to pursue Hunter's derivative subclasses.
Dragon Slayer Skills
Known Dragon Slayers