Noah didn't forget about the Odrea nation and its Mausoleum. Actually, he was interested in the nature of that place.
At first, he had learnt to accept it as a training area that the Empire used to skim its army. The official story was that a rival of the god of the Empire had lost the race to the divine ranks. That made the entire nation suffer from that.
Yet, that was just the knowledge passed down by human cultivators. The records retrieved in the Mortal Palace had shown some discrepancies in that story.
The Odrea nation would have been in that state for more than thirty thousand years if both stories were true, which was something than Noah found it hard to believe. An organization made only of a few thousand human cultivators couldn't have lasted so much.
There was some secret there. Still, the presence of the god of the Empire had forced the few curious experts to give up on its exploration.
