As mentioned in the past, the twins are in the Fortium Continent, mainly controlled by humanoid races. There were many Demon Best territories here, but nothing that could really cause a problem for the humanoid races.
Rean, Roan, and Kentucky didn't want to stay here, though. Instead, they were now heading to the Queintin Continent. That's also known as the Demon Beasts Continent. The reason for this journey was quite simple. They needed a Dragon Race Blood or a Dragonkin Race Blood. There were no real Dragons on this planet, according to the network. However, there were Dragonkin ones.
Roan said in the past that it was enough. He could simply acquire more of Dragonkin Blood from races related to Dragon and then refine the blood until he extracted only the necessary properties.