Arial internal energy combined with his talent of understanding the flow of the energy in one's own body make his training effortless but he could not really be called a genius in martial art technique.
His tactic in battlefield and in politic can be attributed to his understanding and practical theory of the world which he learns during the darkest time in Human History and his internal energy level can be attributed to either divine intervention or luck.
After all, if not for his luck, it is unthinkable for him to reach so high level of mastery in internal energy cultivation.
If it's not for his luck and perseverance, could he have discovered such technique on the Library?
Of course right now the Imperial Library is under the Chu family but Arial is not so worried about it.
Not only you will not find the Library unless you really looked for it but also it is hard to find it.