In an alternate universe, Eren performs a partial Rumbling and makes a deal with Ymir to live a long life even while he possesses the Attack, Founding, and Warhammer Titans, thus slowly losing his humanity, the one thing that he wanted to protect and nurture in himself. Day by day, he started killing his people in gruesome ways if they disobeyed his orders. Many soon gave him the title of Lord Ruler since it seemed that he was immortal. The man forgot how to love even the people that he had sworn to protect. And so, when people thought that only the Alliance members could help overthrow him, he killed them all in a matter of seconds, thus becoming the Complete Titan. Can someone make him realize that it's necessary to give up his thirst for an unending amount of power? How does it take place after centuries of him being in power?