Judging from the stamina and power of an advanced level zombie, they were much stronger than mutated zombies. The most obvious difference was that they already regained some intelligence.
A mutated zombie like Ye Lian merely started to have signs of regaining their intelligence.
That female zombie who wasn't wearing any underwear obviously had self-awareness. Perhaps it wasn't complete, but it was a huge jump compared to those who only acted based on their instincts.
It was imaginable that she would turn into a slaughter machine if she had more chances to evolve.
Lurking inside this mall meant that she would have had enough food sources for a long period of time. More mutated zombies would appear and become the nutrient for her evolution. But Ling Mo's sudden appearance with the girls made her lose her life.
It was the first time that Ling Mo was injured and almost got killed since he mastered his ability to control zombies.