I Transformed into an Oni Warrior on the Brink of Death and Uncovered a World-Shaking Secret

Are There Any Dark Novels with a Ruthless Male Lead Who Kills the Saintly Types First?

I want to read books similar to "After Dying One Hundred Thousand Times, I Become a God in the Strange World." Strange phenomena are reviving, but not the national-organization type. I absolutely do not want useless teammates, something like Fang Xiu.

The Male Lead Has Both Romance and Friendship Arcs, Practices Martial Arts Rather Than Cultivation, and Has No System

Looking for books similar to Long Tai Tou. Everyone in the main group has their own role to play, and the male lead isn't necessarily the strongest. He makes steady progress, one step at a time. He has both a romantic storyline and friendships, and there's no System. Similar to Fu Qin De Ren's Bu Liang Zhi Shui Yu Zheng Feng.

Any Books Where the Protagonist Transforms into a Netherworld Demon?