Summoned With a Demonic System

To surpass monsters, one must be willing to abandon its humanity. And when there is no hope left, what will keep you going? ============= [You have been selected~] When thousands of people around the Earth came across a strange message that floated before their eyes and were forcibly teleported to another world, what must they do to return to their original homeland? Cloud C. Potter, is a 17-year-old boy who was teleported to Ascaris and left behind to be killed by the monsters that endlessly roamed the wastelands of Ascaris. Faced with a life-or-death situation, he abdicated all he had left using a forbidden spell and fell helplessly into the deep abyss of darkness. But when all seemed lost, a mysterious ring gave him a new chance to live: [You have acquired the ??????? succession system] Now armed with his knowledge and his recently acquired system, will Cloud be able to uncover the truth behind it all and take revenge against the ones who betrayed him?