Complex sentence: Once an apprentice of Brewster's in the order of "Goodguy Knights," Dirk is now his arch rival and member of the evil corporation "Microsith," which is currently known as "Numesis".
Split into simpler sentences: Once an apprentice of Brewster's in the order of Goodguy Knights, he is now his arch rival. A member of the evil corporation Microsith, which is currently known as "Numesis".