How dare they ?

The child born to one of the concubines is a still born, while the other is a boy. The princess gave birth to a girl. They were born in the wee hours of new year's day. The mothers fainted after the hard labor, thus, they have no idea their children are switched. Thus, everyone was in a happy celebratory mood until the emperor awoke.

The moment the emperor awoke, he searched for the latest prince and princess using spirit sense. Spirit sense is akin to a radar, with in a certain area, the being with more spiritual power will be able to sense the blessed with lower spiritual power. Every person has some spirit power. Blessed have more spiritual power than normal human being. Some of the blessed have hold spirit power unimaginable by the other beings, including fellow blessed. Most blessed with greater blessings are like that.