MPD Psycho(1996)

Tajuu Jinkaku Tantei Psycho

Police detective Yosuke Kobayashi's life is changed forever after a serial killer notices something "special" about him. That same killer mutilates Kobayashi's wife and kick-starts a "multiple personality battle" within Kobayashi that pushes him into a complex tempest of interconnected deviants and evil forces. Earning praise for its consistently shocking plot lines and Tajima's clean, arresting art style, MPD-Psycho is the manga event of the decade!

(Source: Dark Horse)