If I Don’t Die Soon, I Will Rule The Demon RealmNewIf I Don’t Die Soon, I’ll Become The Ruler Of The Demon Realm!; 再不死我就统治魔界了

Humanitys strongest warrior was killed by demons amidst a battle and gained the power to reincarnate, but somehow did so as a demon. Only by dying he can go back to living as a human, so he committed suicide non-stop. But things turned out to be the opposite of what he expected