After Ten Thousand Years of Immortality, I Became the Villain's Sidekick

After Ten Thousand Years of Immortality, I Became the Villain's Sidekick Plot:

Gu Yuan, an ancient great demon who has lived for 100,000 years and once turned the fairy and demon realms upside down alone, now huddles in a street-corner milk tea shop as the "exclusive sidekick" of Su Xiaoman, a 17-year-old cute new villain. He helps her compete for the top spot on the neighboring school's "villain leaderboard", hides her fear-of-darkness nightlight, and even blocks the immortal sect's pursuit for her. But who would have thought this little girl, who clings to his arm to avoid cats, is actually the "Lord of Chaos" he sealed with his own hands? And in Gu Yuan's smiling eyes lies a bigger secret—he has waited ten thousand years for this moment, to repay every debt he owed her back then.