Killing Demons: I Have a Demon Prison

Demons are raging, evil spirits are everywhere, and the human race is facing an existential crisis. Gu Shimin traveled through time and became a trainee demon slayer in the Demon Suppression Division. After joining the Demon Suppression Division, from now on I can only kill demons until I die in battle. Fortunately, Gu Shimin has a demon prison in his mind. Killing the demons can capture their demonic origins and imprison them, thus assisting in the great cause of cultivation. "The day after tomorrow, the pig demon will offer you three drops of essence and blood, ten kilograms of demon meat, a pair of demon bones, and a piece of demon skin!" "The demon in the middle stage of Xiantian has cultivated the Vajra Body for you, and the technique is perfect!" "The snake demon in the late-stage extraordinary stage has cultivated divine weapons for you and tempered the poison of divine souls!" "The Holy Realm Perfection Demon King will make an elixir for you and obtain the Seven Mysterious Treasure Pills!" Gu Shimin set his sights on countless demons in the world. "Taking people as great medicine? You monsters seem to have some misunderstanding. To me, you are the great medicine!"