Please recommend me some (in the title) novels. It is better if it have harem or romantic subplot, but its still okay as long as the mc is evil and ruthless. P.s. One of my favorite is Reverend Insanity. P.p.s. I also like the plot of Soul of Negary.
It kinda sweet but at the same it also grim that bring chill to my spine, so I guess it's Dark Fantasy. https://www.novelupdates.com/series/tale-of-an-edible-girl/ Only for people with brave heart and have healthy amount of endurance in morbid fiction.