I'm Really Not the Demon King, It's All Thanks to the System's Delusions

I got punished by my teacher and had to stand in the corner, but the System said 【Ding! The Demon King has voluntarily given up his throne and chosen self-exile!】 I walked a little slowly, and the System said again 【Ding! Faced with low-level monsters, the great Demon King still strolls at his leisure!】 I fed a stray dog, and the System went into overdrive 【Ding! The Demon King is feeding his loyal retainer!】 Han Xu: “...” No. I really am not the Demon King! After transmigrating into a high-martial world where everyone could become a hero, Han Xu was just a level-one bottom-feeder. His Source Sea leaked, his stats were low, the college entrance exam was coming up, and he was dirt poor. That was until he bound himself to the wildly overactive [Final Demon King System]. From then on, no matter what he did, the System could explain it as something a Demon King would do. Spacing out meant surveying all living beings. Standing in the corner meant self-exile. Walking meant scorning the abyss. The most ridiculous part was The more wildly the System imagined things, the stronger he became. And so Han Xu discovered a problem. It seemed... He really could become the Demon King.