The only reason why Khaos didn't shift into his beast was because, it would expose his identity. It would cause an uproar and obviously, he wouldn't live right now if they learned he was the lycan.
The lycan beast was different from their werewolf form. They were bigger, faster and stronger. Their distinctive features couldn't be mistaken.
That was why, Khaos had never shifted into his beast, unless it was necessary or he was with his people.
However, despite Khaos couldn't shift into his beast form, he was excellent with swords, though he had never showed his skills openly, since he would be the mastermind behind all the attack or defense for the kingdom, because he 'couldn't' shift.
As someone, who controlled the defense of the kingdom and had hundred of thousand warriors under his command, this position benefited Khaos more than if he put himself on the throne.
