One objective down, many to go... Tonight I finished my personal story by killing Zhaitan inside the Arah instance. The instance is quite fun except for, surprisingly, the last part when Zhaitan himself is engaged. All you have to do then is to stand by a cannon and fire on him. You don't even need to target him. Just press '2' every other second and the match is won. A bit strange, but perhaps it is a different story when doing the instance in exploration mode. Time will tell!
But for now, I'm happy to be done with my personal story, and looking forward to go explore the rest of the game!