In the old book section, Vaan did not select a particular topic to focus on. He had covered all subjects. Whether they were plants, races, maps, or history, he had gained a general understanding of each.
To begin with, the old book section only covered general to basic knowledge. More advanced knowledge was locked behind price tags.
Even so, such rudimentary knowledge was enough for Vaan to lay a solid foundation of understanding regarding the Myriad Sea God Palace. At the very least, he wouldn't be stumped by mistakes and encounter avoidable troubles or dangers.
Of course, even if Vaan didn't voluntarily look for them, they might still come looking for him.
Vaan still had yet to ascertain whether the Myriad Sea God Palace could shield him from the heavenly tribulation.
However, staying in Pangea and Gehenna would only put his people in danger.
