How Dare You Mess with Him in Another World? in His Previous Life, He Was a Global Sensation

He was a top psychologist in his previous life, and he was reincarnated into a different world called a nightmare. As one of the seven ancient demon gods, Nightmare Savinas has seen your power with his own hands and bestowed upon you a blessing. And I tell you that the ancient magic sword was pulled out in the dream. You must find it, master the power of all evil in the world, and become the master! As a scumbag with heinous crimes in your previous life, you passed away because you were tired of the injustice and hypocrisy of your previous life. With this world-weary mentality, you have mastered an unprecedented power in another world, called the power of "world-weariness". By hating the world, you become incredibly powerful!