Complex sentence: He was a younger brother of Ravana, and was killed by Rama when he attacked Rama after Shurpanakha's humiliation.When Lakshmana cut Surpanaka's nose, Khara went and fought against Lakshmana and Rama.
Split into simpler sentences: He was a younger brother of Ravana, and was killed by Rama when he attacked Rama after Shurpanakha's humiliation. After Lakshmana cut off Surpanaka's nose, Khara went and fought against Lakshmana and Rama.