"They die to give me pleasure!" - Sir William while fighting.
Representing the sin of lust, Sir William is a paladin and the ruler of the city of Heaven's Peak. He was convinced by the Wizard, to give up his days of protecting the weak from evil and is now interested exclusively in sensual pleasures.
History
Returning to Heaven's Peak as one of the Seven Heroes, who killed the Second Overlord, the people of Heaven's Peak said that he was not the same as before he left. Also about the same time he returned a zombie plague had infested the city. After doing some quick searching, you discover that the Wizard had convinced Sir William to stop helping others and to only care for his own pleasures. You also discover that he formed a cult, called the Red Dawn, to help him summon a Succubus Queen, Who he had been cheating on his fiancée Velvet with. This is also what turns out to be causing the plague on Heavens Peak.
Overlord
You fight him in Angelis Keep. After spotting you he is surprised you are alive, then angry that you show up and have not followed his dress code. When he is defeated he falls to his knees in the middle of his cult and explodes into a cloud of billowing black smoke, blowing some of his monks away. This also leaves Velvet open for a new husband, as potential Overlord mistress material. During your first encounter with him, he says "Didn't we leave you for dead in that Godforsaken Tower?". It is unknown if he meant the Second Overlord or the 8th Hero (referring to the Third Overlord when he was still a hero).
Overlord: Raising Hell
He and his cultist followers, The Red Dawn, are punished by being set on fire in the Heaven's Peak Abyss, and the paladin is dragged into a cleaner to clean people's belongings and do various household chores and is ultimately defeated after a foolish attempt to capture the abyss stone for himself.
Sir William's Torture.
Personality and Traits
He represents the sin of lust, and battles with magical abilities and a staff. He also has the face of a lady's man, and has a thing for following dress code.
He interestingly is very similar to Prince Prospero in Edgar Allan Poe's Masque of the Red Death.