It sounds like you have completed all of the available main story quests. I'm assuming you're talking about the story quest segment with the white robed Ascian that is available after defeating the moogle king. The only other story quest available at this time opens up after you defeat Turn 5 in Binding Coil of Behemoth, unless you have already completed this as well. If not, it's just a small talk-to-people chain to wrap up the story from Coil.