"Angel"

"The gap between the skull and the metal skull has narrowed, but it hasn't been excessively squeezed." Neil put down the instrument and explained, "It may be that your superpower level is relatively low, and your bone regeneration ability is weaker, which causes the metal to be squeezed but not pushed out; at the moment, it doesn't appear to be a major concern."

"Do I need to change a bone?"

Neil hesitated before responding, "You do, in fact, require one. But the key is that your bone regeneration ability is weak. If we remove the metal skull, your bones won't be able to grow back fast enough to fill the skull gap on their own. We still need to install a small metal bone piece on top of it, like changing to a new fitting number. It can be predicted that your metal skull fitting number will continue to change, and perhaps in the future, your bone regeneration ability can fill the skull gap on its own."