Because Russel was not a noble, he was left in the Cres Val mansion with Aaron. It does not really matter to him. Those things such as oracle and saintess did not attract his attention. Not even a bit.
So Russel was left behind in the mansion. He decided to stay in Gian's office and read some of the books placed in the bookshelf. The truth is, Gian gave him a book to read. The book was all about the history of the Fresiala Kingdom and its political law. Since Russel will temporarily live as a human for a few more days, then it was better for him to know about these things.
But of course, Russel did not read it. Just like what he had said, he was not interested in their political history. But it does not mean he cannot understand its content. Russel was not reading those books not because it was too boring for him. The real reason was he already understood their law and the kingdom's history and its political flow.
