This book changes a lot of our misconceptions about Raavan as a sentient being.
First of all, he is described as a Naga, or a mutant. Jain scriptures categorise him as a demi- God.
I think of him as a tragic character. His back story reveals him to be a victim of an abusive father. His father was disappointed with him and did not care enough about his child's feelings. At least,not enough to hide his disppointment. Kumbkarna, Raavan's younger brother, was also born a mutant. He was the only person that Raavan loved and could be his true self with.
Raavan was a genius. His intellect was that of ten beings. Unfortunately he had a strong latent streak of violence that was his undoing.
The journey of Raavan's soul is mapped in the Jain scriptures. In the next time cycle, he is going to be an omniscient. No soul is perfect, but Raavan's tremendous personality, finally takes him on the right moral path. Even so, it takes him a few more incarnations.
Author Amish Tripathi has this great talent for making his characters so believable. Given his penchant for mythological characters, this is quite a feat.