MTL - Transmigration: Raising the Child of the Male Lead Boss - Chapter 21

The story is about a man who’s opposed to the now-common practice of implanting false memories, but is one day given memories of a fictional childhood friend. This fabricated happiness torments him, but then, to his surprise, he meets her – a girl who shouldn’t exist.

Shao Qing’s only regret in life is that she blindly fell in love with a worthless man. She gave up everything for him, but in exchange was run over by his conniving mistress when she was close to her delivery date. Fortunately, Heaven left her a way. Crimson rain fell from the sky, the end of the world arrived, she resurrected in the morgue and gave birth to a little monster. Turning into a half human, half zombie freak; her son neither human, nor monster; they have no other choice but to rely on zombies’ crystal nuclei to develop their special abilities and continue living. This debt, she’ll definitely repay that cheating couple!

- Description from Novelupdates

When necromancers perform a great ritual to summon an undead servant, they bring a powerful vampire into their world. And now, their fate is sealed as food, but for Klaus, this is just the beginning of his adventure. In a cruel world where people will do anything for power and immortality, he is already very strong and immortal, so what's left if not start a family and have fun stepping on arrogant people through the way?

Crossing to One Piece world, he became Roger’s younger brother.