Alexander Perryl, real name unknown, age unknown.
He was the son of a fallen aristocratic family, who luckily became a knight under the Order of Thistle. Due to his complicated background, he could not be Arlan's official guardian knight, but in fact, he was the leader of the dark forces secretly run by Arlan.. He was a trained knight and his swordsmanship skills were only slightly worse than his captain, but rather than his fighting prowess, his strongest weapon was his talent in intelligence-gathering.
Calculative, sensitive and with a good understanding of people, in addition to his leadership skills and strong loyalty, Alexander was the best person to deal with the prince's dirty work, actions that would earn severe criticism were they to surface in the light.
The Crown Prince's dark force was an intelligence-gathering organization solely working under his orders, and it had nothing to do with the King of Griven or the kingdom.