Mystic Kinesis Art refined minerals while Mystic Sumatra Art refined Pranic Beast bodies. A Brully stood perfectly within the domain enveloped by the two.
Using Mystic Sumatra Art, a Brully could refine its body, which also included its hands, that were made of a mineral. It was the sole existence that could take advantage of the effects of te two cultivation techniques.
The mineral of Rutham enhanced the range and power of psychokinesis. That was its sole function. A Roshmon was a Pranic Beast created to specifically harness one aspect of Rutham's characteristics. The Brimgan Founder had specifically created it.
Back in his days, only a Primary Nature was possible for Free Humans. Pranic Beasts were different, as they could mutate and gain a Secondary Nature. Therefore, he laid down plans, to create a blueprint that his successors could follow and one day figure out how to gain a Secondary Nature.