Complex sentence: Kirmira was a Rakshasa, the brother of Bakasura, who lived in the Kamyaka Forest, and used to terrorize the Rishis who inhabited that forest.
Split into simpler sentences: Kirmira was a Rakshasa, the brother of Bakasura. He lived in the forest of Kamyaka, and used to terrorize the Rishis who inhabited that forest.