I roleplayed a necrophiliac, starting with the Dunmer woman draped over a log at an unmarked Bandit Camp on the way to Falkreath. He also Destroyed the DBH, and defiled Gabriela on the table in the crafting room. Mostly stuck to an Elven victimology, Dark, and Wood womer. (Altmer are too tall.) Couldn't resist Brelas chained up in the basement of Elenwen's Solar, terrorized any one wandering the Gray Quarter alone, until he ran out. As a bit of a departure from the IRL profile, his victimology was not of his own race (Nord) suggesting a racial motivation.
Since there is no sex in Skyrim (Availible to the character) I guess he was more of a Sexually Motivated Serial Killer (Picarist.) He displaced to Stabbing in the face, chest, and abdomen, long after their death, stripping, and displaying/posing the bodies, and post mortem mutilation... used the dagger left handed for Power Attacks, symbolizing Evil, and simulating the exhaustion cased by stabbing them over, and over, and having to rest before continuing. (With interludes of stripping, posing, and playing with the bodies.)