I Am Invincible After Death. Who Said This?

Liu Yu became invincible after his death. After killing all the strange beasts in the world, he looked at the devastated world, allowing his relatives and friends to be reborn with memories and go back to the past to kill his newly awakened self. Then, my sister followed Liu Yu all day long, always ready to poison him. My sister established the largest killer organization with the sole purpose of killing Liu Yu! The good brothers established the largest church and promoted that killing Liu Yu could save the world. Liu Yu: "You are all so sick! Who spread the word that you will become invincible after death? If you die, I will never die!" Sister: "What should I do if my brother is too difficult to kill? I have to wait online in a hurry!" Future Liu Yu: "Was I so hard to kill in the past? If I don't die, I will be almost invincible while alive. Is it necessary to die?"