He will obey the orders of the royalty, no matter how much he disagrees with it because he believes it's in the best interests of the kingdom. Unfortunately, he's obeying the orders of Keera. He was strongly morally opposed to Keera's intentions towards Shera, but as the crown prince, Kiira's word is the law of the land in the Greenwood Kingdom. Selsio chose "lawful" and came to regret it, though choosing "good" wasn't likely to go very well either.