This page explains how to obtain Ending 9: “The Dragon God’s Revenge” in Chrono Cross: The Radical Dreamers Edition.
How to Obtain Ending 9
To acquire this depressing ending, you must defeat the Time Devourer after completing Chronopolis and before completing Terra Tower.
Like all the other alternate endings, you must return to Opassa Beach and use the Time Egg to fight and defeat the Time Devourer. For tips, please check the linked page.
Party-wise, this is the most flexibility you’ll have, since you’re almost near the end of the game. You could even use the Chrono Cross to re-obtain characters you previously recruited in your cleared save file, including powerful characters like Glenn and Harle.
The ending begins on Sky Dragon Isle where the Dragon God has subdued all its enemies. You’ll then witness life at El Nido with humans no longer at the top of the food chain…