The second and third level of the quarry was only divided by a small boundary. Once a player passed through it they would instantly appear on the next level. Furthermore, passing through the boundary would reset the aggro players drew. Hence the moment that Wang Yu reached the second level, all the aggro that he had from the zombies had already disappeared.
Nonetheless, Wang Yu still felt some pressure seeing all these zombies. Ever since the Zombie King had commanded them with its roar, these monsters were considered part of the hidden quest and all received buffs.
No matter how confident Wang Yu was, he wouldn't fight so many level 30 zombies at the same time.
When he first explored the third level, Wang Yu had already noticed that these monsters all possessed high physical defense. So the moment the Zombie King summoned the Zombies Wang Yu immediately tried to flee. With his new Sunset Warboots, escaping wouldn't have been a problem for him.