Well, it should have been expected. The next boss was just another bash fest. Even with its magic barrier, Larstastnaras proved to be no match for my group of four.
However. Now I'm really feeling the consequences of playing this game out of order.
It's entirely possible that the people of Batsureg wouldn't give clues for the next fygg anyway, but this seems unlikely. In a game as expansive as Dragon Quest IX I expect there to always be a hint hidden within NPC dialogue.
Since it's unclear where to go next I've taken to my ship.
Sailing around has landed me in the area of Wormwood Creek. Here, the entire town refuses to interact with foreigners. There's definitely a major sidequest here since what the people of Wormwood Creek do say suggests there's a way to break the town of its xenophobia. All of which is backed up by an inscription found at the edge of a canyon.
Now, the question is: Am I heading in the right direction?
I get the feeling that this part of the game (though in a hitherto unexplored part of its world) is extra. This feeling probably comes from the obscurity of it all.
A town that rejects foreigners?
An area that's mostly open space?
It just feels too far flung to be part of the game proper.
As always though, I won't know until I play further in. (And as long as I ignore most of what one of the linked pages mention.)