Xiǎoshuō zhōng de fǎnpài shì yīgè wēixiǎn de sèqíngkuáng.
The villain in the novel is a dangerous sex maniac.
Tips
usage
色情狂 is a clinical-sounding but highly derogatory label. -狂 (kuáng) is a suffix meaning 'maniac/obsessive', used in both clinical (偏执狂) and informal (追星狂) contexts.