Black-Eyed Zombie from the Start, Leveling Up by Scoring Lucky Finds

[No Female Lead + System + Apocalypse + Humor + Deviates from the Original Plot + Working Hard to Update Like Crazy] Zombies are born from the resentment of heaven and earth. They neither age, die, nor perish. Outside the six realms of existence, they wander without a home, gathering the resentment of the living within themselves. They possess immense strength and are impervious to blades and bullets, using the blood of the living to vent their endless loneliness! After dying, Zhang Feiyu transmigrates into the world of My Date with a Vampire. To his surprise, he's only a black-eyed zombie from the start. Then he keeps leveling up and fighting monsters... while picking up all sorts of easy wins. He takes in a lackey named Kuang Tianyou. He punches Yingchen and kicks the Holy Mother. Nuwa, bring me a footbath... Wake up, Zhang Feiyu. It's time to go pick up another easy win. Zombie ranks: red, green, yellow (orange), blue, gray, black. From then on, they all have black eyes, and their abilities grow weaker and weaker. Purple-eyed zombies exist independently. Their strength is around that of red-eyed zombies, or even greater! But do you know what color eyes belong to zombies even stronger than these?