After Darius and Old Fang entered the Cultivation Chamber, the wolf told Darius to sit in front of him. Therefore, Old Fang imparted the Law of Beast Cultivation Art into Darius' mind, body and soul.
It didn't take too long for Darius to understand the groundwork since Alexa was also there to help him comprehend the law.
Unlike Magic Cultivation which mainly focused on cultivating Arcane Energy from outside sources and enhancing one's brains capability to comprehend complex spells and formation, Beast Cultivation Art, on the other hand, was more straightforward and focused on strengthening the body to withstand devastating techniques that could only be performed by the Magical Beast due to the sheer force of Arcane Energy.
"Interesting." Darius smirked. "So, this is how Magical Beasts get stronger over time. The method is crude compared to Magic Cultivation and yet it has unfathomable potential."