Mirai no Kuromakukei Akuyaku Reijou Moriarty no Isekai Kanzen Hanzai Hakusho

A brilliant criminal, known for his intellect, is killed after a final showdown with a renowned detective. He is then possessed by a young woman from another world who has suffered mistreatment at the hands of noble girls. Despite losing his memories, his sharp mind remains intact. Using his strategic thinking and mastery of criminal tactics, he works to protect this one girl in a world where the great detective no longer exists. The abused girl, in turn, is reborn as Moriarty, carrying out her plans without emotion or hesitation.