Ravan was an Ayurveda scholar and the author of Ravan Samhita .He could play Rudra Veena .He was a veda scholar and learnt all veda’s by heart. Inspite of the fact that he is a demon he is still worshipped in many parts of India and Sri lanka.He is revered devotee of Lord Shiva and even created Shiv Tandav Strotram to appease Rudra’s anger.He broke Shani dev’s leg .Even while dying he taught governance to Lakshman . He had a boon from Brahma that no god, demon, kinnar or Gandharva could kill him .So Vishnu had to take incarnation in form of Manav to kill him . He defeated god’s multiple times .All these facts testify that his fighting, statesmanship and devotion and that makes him the most awesome Villain of mythology.
He also tried his luck against Bali, however Bali punched him hard ,folded him and held him under his armpit. He took him to kishkindha and held him captive there.Ravan negotiated with him and they became friends.