There was a massive difference between hunting level three magical beasts and branching experts, and it all boiled down to the Qi.
While magical beasts also had access to that energy, occasionally developing powerful abilities, they were limited to its rawest and most basic uses.
Instead, the Qi mastery was an entire field for cultivators, spanning from the uses of its rawest form to the most majestic techniques in the world.
The Qi mastery alone might be inferior to the magical beasts' physical prowess, but proper techniques definitely weren't. They were what made cultivators superior, and what Liam and Lancelot couldn't possibly match even if they had access to rank 3 martial arts.
Dominic's Qi would always make his techniques stronger.
Cultivators were also likely to wield a flexibility that magical beasts couldn't possess. The latter were limited to what their species had provided, but the former could build complete arsenals able to deal with any situation.
