The Devil Reincarnated into a Commoner: He Was Stepped on by the Princess at the Beginning

[Another world + Demon King reincarnation + Systemless + Farming + Multiple supporting female characters and dependents] In my previous life, I was the demon king in charge of nothingness. In this life, I am a waste with zero magic power. — In order to disguise myself, I became the exclusive knight of the imperial princess Arya, washing her clothes during the day and keeping vigil for her at night. She made things difficult for me and asked me to serve in the bath. I used the "Abyss Heart Barrier" to make her understand that the face and body of the number one in the kingdom were no different from a stone in my eyes. She humiliated me and asked me to be the background at the state banquet. I said a few words and caused the provocative young master to die socially. — She thought she had control over me, but she didn't know that every time she thought she was "training", she was frantically testing me on the edge of the abyss. — Until the overthrow of the royal power and the bloody night banquet, she lost everything and said "I'm so scared" while trembling in my arms. I finally decided not to pretend anymore. — When I unfold the [Abyss Realm] and crush the legendary killer into pulp; When I chant forbidden incantations, sign contracts with living people, and turn them into loyal relatives; When the legendary sword master was amazed by the power of my sword... — Arya finally looked at me with a mixture of fear and fascination, and asked tremblingly: "What... Are you?" — I stroked her cheek, smiled and replied softly: "Your knight, that's all. Come on, Your Highness, let's take back your kingdom."