A Celestial War with Time

Earth was crashed into. What crashed it? An advanced Celestial planetary body. The extraterrestrial beings themselves didn't know how their gravitational pull gave out or if it even did, but that didn't stop their rogues, beast and ideology from wreaking havoc on a planet they deem inferior. And Koran and his family were in the middle of it, they witnessed the crash, destruction, felt it even. The moment they saw humanity betray one another they officially knew it was the end, nothing would save them, their world was now lawless. Food once considered bland became flavourful, cult sacrifices seen once as primitive were now used to appease a god they thought to have angered, everything had a say, murder, pleasure, warlords, slaves, traitors who even worked with the extraterrestrial beings Koran learns through loss, scars and allies that the only way to take down the extraterrestrials was using the one thing they trusted too much, Time.