One of Lord Shiva’s greatest devotees was Ravana, the demon king of Lanka, who was the main antagonist in The Ramayana, the story of Lord Rama (avatar of Lord Vishnu).
Ravana was a Brahmin and a great scholar and very knowledgeable in the Hindu scriptures . He has even moved Lord Shiva with his prayers and austerities to bless him with boons. However the biggest flaw in Ravana was his massive ego (represented by his 10 heads).
It goes to show that works of such power and beauty and transcendence can come from a demon like Ravana too.
Here’s a nice version of it —