Complex sentence: Karna was a great warrior in the Kurukshetra war and his story is contained within the Mahābhārata, as is the Bhagavad Gita, a sacred text of the Hindus.
Split into simpler sentences: Karna was a great warrior in the Kurukshetra war. Contained within the Mahābhārata is the Bhagavad Gita, the sacred text of the Hindus.