Alright, so how the demon emperor gets his power is basically the core of his whole tragic backstory and rebirth arc. It's not one event, it's a brutal, multi-stage process. He starts as Lin Ming, this genius cultivator who gets betrayed and murdered by his own sect and fiancée. That death and the soul-crushing resentment is the initial spark—it fuels his will to defy the heavens themselves. But the real power surge comes from the 'Nine Revolutions Demon Sovereign' inheritance he stumbles into during his soul's wandering after death. It's a legacy from an ancient, fallen demonic god that requires him to temper his body and spirit through nine near-impossible tribulations, each more agonizing than the last. What I find compelling is how his 'defiance' isn't just a cool title; every ounce of power is literally wrested from fate through suffering, sacrifice, and constantly breaking through the limits the world tries to impose on him. He doesn't just find a manual and train; he seizes opportunities during desperate battles, makes ruthless pacts, and constantly refines his techniques through failure. It's a violent, messy, and deeply personal acquisition.
Also, don't forget the psychological component. His previous life's knowledge gives him strategic foresight, but his paranoia and trauma from betrayal become a kind of power too, driving him to be more cunning and prepared than anyone else. The 'fate-defying' part is as much about his mindset as it is about cosmic energy levels.