Conjoined Twin?

Grey fought against the duo for some time and he wasn't at a disadvantage. The black-horned man might have good spatial prowess, but there were not enough techniques for him to properly utilize it. Ultimately, it all came down to the fact that they mostly used their physical strength for battle. 

When the duo noticed that Grey was not at a disadvantage against them, their shock started to turn to fear. Grey was still in the Seventh stage of the Overlord Plane, if he managed to get to the Peak of the Overlord Plane, then he could move unhindered in this place. 

Someone like Grey was a catastrophe for their race, especially given how they treated humans. Unknown to them, Grey didn't really care about how they treated humans, as long as they didn't bother him, he wouldn't be too concerned about them.