Secrets of the realm.

When Cassius first came to Infinite realm, he was even more confused than Blake. However, unlike Blake, he had no Prince Bryon to guide him on what to do.

The only good news was that Infinite Realm was at its peak at that time. Not only were Magic schools available in every city, but cultivation resources were easier to get, thus making it easier to advance.

Long story short, after a century of hard work and dedication, Cassius finally became the human deity of darkness. This increased his connection with the Mother-stream which revealed to him a vision of his purpose in the realm.

"Outside our universe lives a race known as the Neons. They are a warmongering race that invades other universes with the aim of draining the Mother-stream dry and moving on to the next universe."