Prediction:
The crown princes brother started the rebellion, gave the Baron the Magic stone to cause the mana surge, causing Sione to go into labor. They took the child (riche) to disrupt the Cerius duchy. Most likely doing stuff like this in various areas. They were most likely hoping for the crown prince to die fighting the pirates but continued the plan when he came back safe. All this to say Prince Haedon is behind everything.
The crown princes brother started the rebellion, gave the Baron the Magic stone to cause the mana surge, causing Sione to go into labor. They took the child (riche) to disrupt the Cerius duchy. Most likely doing stuff like this in various areas. They were most likely hoping for the crown prince to die fighting the pirates but continued the plan when he came back safe. All this to say Prince Haedon is behind everything.