They Took My Blood and Bones for My Brother, as Payment for What My Parents Owed Me

[Light System + insanely satisfying revenge + killing older and younger brothers + parents regret it + the God of Slaughter awakens + absolutely no forgiveness + invincible among peers + not invincible from the start] Zhou Ping'an was born with a sacred physique, a holy aspect, sacred blood, and sacred bones. He was destined to become a saint whose name would resound through the ages. His father was the King of Zhou, who kept dozens of provinces in check, and his mother was Xu, the Sword Immortal whose blade-light shone across the Nine Provinces. He was destined for a glorious rise. But his birth was nothing more than a cruel joke, brought about by his parents' desire to save their eldest son. His sacred blood became the life-saving medicine his older brother needed. To prevent that sacred blood from going berserk inside his brother, his parents abandoned Zhou Ping'an at their ancestral home in the countryside, leaving him to fend for himself. Three years later, Zhou Ping'an waited eagerly for his parents to come, thinking they had returned to take him home. Instead, they dug out his sacred bones for his newborn younger brother. Eighteen years later, Zhou Ping'an was brought back home, where he became a spoiled good-for-nothing who loved to eat and never studied. Worst of all, he couldn't cultivate and was destined to remain an ordinary mortal for the rest of his life. He thought his blood and bones would at least guarantee him a comfortable life, but his parents didn't love him, his brothers mocked him, and even the household servants looked down on him. At long last, someone seemed to love him, only for him to discover it had all been a game controlled by someone else. From beginning to end, he had been utterly alone. If that's how it is, then he's done pretending! I'm the God of Slaughter. Here's the truth! "Brother, the sacred blood in your body is exactly the color of my Imperial Banner!" "Little brother, the sacred bones in your body are exactly what my Imperial Banner's shaft is made of!" "Father, Mother, if I've ended up with the whole world against me, it's all thanks to you! Since you two favor them so much, why don't you come for a chat inside my Imperial Banner?"