Fruegel is the head warden of Hellena Prison, he is feared by most because of his emense size and power that he shows throughout the battles. HE has major problems controlling his anger, thus it is shown many times that he kills his own men, or bullies them.
Attack on Seles
Seles was ordered to be raided and destroyed by Fruegel, although he is not seen in the video during the raid, it is hinted by the head Commander during your visit to the castle to fight Emperor Doel. The original intention of the attack was just to obtain Shana, but he didn't consider that to be enough, so he ordered the raid also.
First Encounter
The first time you meet Fruegel is just at the exit of Hellena after you have rescued Shana, and are escaping. You battle him and then steal the horses beside him. During the first battle he isn't that much of a challenge considering he only has 90 hp, but he does pack a powerful punch.
Second Encounter
The second time you actually encounter Fruegel is when you are on your way back to the prison, except this time you are rescuing King Albert from his grasp. After defeating his pet, you make your way up the stairs to find him just about to kill him. You engage him in battle, this time he is a bit harder considering he now has 1000 hp and has two pets that each contain 400 hp. It is never really said if he dies or not, but it is hinted that he was becasuse you don't see him after the battle.