The figure of Rhizen slowly turned transparent before becoming a ray of Mental Energy that swam through the Origin Art of Mind Connect, arriving in Compass Carburettor's mind space.
Rhizen's second fusion material was the Mental Energy sphere he obtained from Compass Carburettor. And at the Martial Providence Stage, it allowed him to take on a Mental Energy form and travel into the mind of others through the Mental Energy streams they emit.
This was only possible if the Mental Energy stream was directed at him though. He could not enter the streams directed at others. Since he already told Compass Carburettor about his ability, all necessary arrangements had been done beforehand.
The moment Rhizen's body arrived in the mind space, his body and mind fused into one as Rhizen began to absorb the Restriction Order, using it as his third fusion material.
Compass Carburettor watched with bated breath as the Restriction Order was actually fusing with Rhizen.