One Piece: Kaido's Adopted Son, the Beasts Pirates' Top Blade

Qin Huai transmigrates to the world of One Piece and is reborn as Ulquiorra Cifer, one of the Espada, from the start. Taking on the form of the “Black-Winged Great Demon,” Qin Huai chooses to join the Beasts Pirates, becoming Kaido’s adopted son and the first blade aboard the Beasts’ ship. When black raindrops fall from the sky, when did you ever get the idea that I could be defeated? (The protagonist is cold-blooded but not saintly, and doesn’t kill indiscriminately. There is no female lead, so read with confidence.)