Sneak In.

Valerian was riding the thunderbird at a speed faster than the troops marching toward borders, he was only stopping for eating, if the thunder falcon was tired, he will let it enter the beast pouch and walk on foot. 

After seeing his urgent behavior, Fortuna suggested, "How about I carry you in my talons and Priscilla ride on Mathiyus?" 

Valerian agreed to it. In his mind, dignity was not as high as the priority of saving lives. He was not someone who liked to play the hero, but he definitely did not wish to see his relatives suffer in this situation. Also, he was enraged by the ploy designed by Sapientia and Valkyrians. He did not like politics at all. 

...

General Un and Ignis were riding their wraiths at full speed ahead at the moment. It will take them two more days to reach the border. The general asked, "Your Highness, any news from the fourth prince?"