Complex sentence: Long ago, in the distant past, they waged an eternal war against each other for the right to become the One True God and rule the world, however every god who participated in the war was defeated and the war ended with no victor.
Split into simpler sentences: Long ago, in the distant past, they waged an eternal war against each other for the right to become the One True God and rule the world. However, every god who participated in the war was defeated, and the war ended with no victor.