Claude had his worries when he asked that question. He wondered whether Jour would let Cale be the crown prince. Jour didn't really want any attention after all. Despite being outgoing. But Jour was very secluded while she stayed with Claude in the Imperial Palace. And she had good reason to.
Jour ate with Claude many times, almost every day since she arrived. Claude got to know her better through those mealtimes. There was one time Jour mentioned her family, the Thames family. It wasn't a famous family but they had a long history with the royal family since they're in charge of shipments of goods from other countries. But as Jour described her family, it became clear why she was hiding.
The Thames family became extinct, relatives of the family were being killed off one by one. It was unclear to people why they were being targeted as they were a neutral family. Only Claude and some others knew why. The Thames family had a special power called 'Annual Rings of Life'. Allowing them to see the passage of time of a person as rings. But they also had another ability that rarely came the members of the Thames family. 'Change Beyond the Reef' to change the destiny of an individual with good reason but never for one's sake. If the rules were broken, the user dies.
Jour and her father were the only living user of the two powers and she did as she wanted with those powers. Change the date for ships in shipwreck, the destination of people in order to meet their soulmate. It was like a hobby of hers, performing especially in a ball where corrupted nobles go to. But people found out about the powers and they became outraged thinking the misery in their lives were the Thames family's fault. That they had changed their lives for the worse. So the people started killing the family, leaving Jour as the last remaining survivor of the chaos. Jour's father who also had the two powers changed Jour's destiny and was killed in the process.
-You can never change your loved one's destiny-
When Claude learned of this story, he knew the answer to his suspicion. Why Jour's mana waves were so strong. She was constantly using her power that the mana flow around her became stronger than before. And Jour was powerful too, she could even top Claude in magic if she wanted to. But Jour never used her powers after she stayed with Claude. She feared her powers would be used by him that could kill her. When she told Claude about her powers, she asked to him to never tell anyone about them and her family. Jour feared Claude but she trusted him with some information that she hope would save her desendants if any. Claude understood this well as his mother would have done the same so he promised her with his life.
That promise was what Claude struggled with however. As Calude wanted to announce Cale as his son, he couldn't let the nobles hear of his mother. It was his promise to her to keep her son safe and raised him well. But if he really wanted to do that, he needed Cale to stand as the crown prince. But not sure of what to do, he turned to the boy himself.
"...Should I?" 'A crown prince..?'
"It depends on you, son" 'Looks just like his mother'
"..sure" 'he called me son..'
"Thank you" 'You will do great'
"Hmm.. A new prince i see.. Thames huh..."
"..This will be fun"
(I'm just gonna change the ancient power to special power cause i wanted the power to be a born-with-it power) (Change Beyond the Reef is a made-up power, sorry if you don't like it 😔)