Although Kence managed to greatly affect Arthur's soul to the point that the man was forced to stop doing any other thing than to defend his soul, it wouldn't work for a second time anymore
No matter what, Arthur is still originally stronger than Kence. Not to mention, he would surely raise his guard up in case Kence tried to do it again
Even then, it still severely injured Arthur and his power drops a lot. Although he is not dying yet, with his power weakened to the point, it puts him in a bit worse of a situation than Kence
Kence has the support of the universe. Despite his heavy wounds, the universe was helping to heal him
While Arthur is being weakened from his injuries, Kence is getting healed from his
In the long run, even if Kence's power drops to what it originally should have been, it would still not be a good thing to Arthur since his power was also weakened greatly
