Determined to Save Humanity, the System Turned Me into a Ghost?

(Demon Slayer fan) Once traveling through time, Fushimi Nagamasa came to this world where ghosts and humans coexisted, determined to kill ghosts and prove enlightenment. However, after absorbing Wu Mei's blood... "Ding! The system has been successfully updated and the overall mission has begun: becoming a new generation of ghost kings!" Fushimi Nagamasa:? ? ?