The "high intelligence" here doesn't mean those degenerated players can think like normal humans and then fight—they're not normal people—but their combat instincts surpass ordinary mutated animals. Unable to respond to human speech, they can to some degree avoid the influence of characteristics and props. Years of life-and-death struggle in game instances have trained them to kill efficiently in critical moments. So, when the nation and government were completely unprepared, Zone 010 lost a massive number of players—those attacked by them also had a certain chance of degenerating.
