The leader of those humans seemed to be Iron Fist Jia Shidao.
When Han Sen joined the Demigod Association, he had come into conflict with Jia Shidao, and it ended pretty badly.
"I can't believe I'm so unlucky. I've finally run into some humans, yet I'm at odds with one of them. Why do I keep running into people I don't want to see?" Han Sen thought.
Jia Shidao was powerful. He had an iron fist glove on his right hand, which seemed to be his geno core. Each strike from that fist left a scar across the scales of that mutant creature.
As for his companions, they were relatively weak. They weren't strong enough to break the creature's scales. When they hit the mutant creature with their blades, they were basically just scratching its back.
That mutant creature looked bizarre. Its body looked like a turtle's, but it didn't have a shell; instead, it was covered by thick scales.