Blue is so warped that calling him crazy seems to be an understatement, his moral compass simply isn't led by principles of normal people. His man, even the most crazed, you could see that they had a connection with the emotional pole and reason to be what they were, he simply... isn't human, Gold was right this guy is really a monster.
In this single chapter, Blue has scaled to be one of the best villains i have seen, up there with Hisoka ( yes, i know Hisoka is more of an antagonist than a villain but you know what i meant ).