Karoline handed him the crystal, and kept dancing around as if she was really waiting for magic to happen. He rolled his eyes, looked at her and didn't say anything when he noticed how excited and happy she was.
He also got why she mistook this as a fortune telling game. During that test, he and others kept assessing masters' talents and potential, while many commented as this was their life turning point and such stuff. She must have taken everything a bit wrongly, though they were seeing their future or something.
It was indeed partially true. Using this method, William could tell if anyone got a good potential or not, would have a bright future ahead of them or not.
He then turned to focus over the crystal he got in his hand. When he saw the little white dots there, he couldn't help but recall the first time he tested his spirit power after coming back from the future.