...…
When Shin returned to the mansion, he was pretty much beaten up from head to toe. He had bruises all over his body, which indicated how much he had suffered from his 'sparring match' with David.
Fortunately, David knew how to hold back as well and only hit Shin where it hurt the most, but would not deal that much damage.
Shin had just broken through and was still stabilizing his realm, so there were a lot of risks if he overworked himself a little too much.
David had skillfully controlled that battle, limiting Shin's abilities and beating him just 'right.'
Ironically, Shin felt a little relieved with his body despite how much of a beating he had suffered. With this, he could tell that David had used some special methods to fix a few things that Shin could not see or sense from his body.