NDS flame indicates light and shadow. The collected fragments got the seal shield, but the pearl of light disappeared. What should I do? Harding can't hit without the pearl of light.

Are you kidding? You must defeat Harding to get the Pearl of Darkness and then synthesize the coat of arms. Harding couldn't get it normally before he died.

So, you must have traded your golden finger for the pearl of darkness, which led to the game error.

The solution is to change the pearl of light. In this way, you can beat Harding again, or directly replace the black pearl on Harding with a wound medicine, and you can pass the exam.