Hearing the behemoth's words that address him in an almost disinterested manner, Mammon frowned. He had vaguely sensed that something was wrong here and now he had confirmed it. He had activated his ability before this behemoth had even entered the fray yet for some reason, he hadn't been able to copy any of the skills the behemoth before he had used so far.
He could accept it if the behemoth was already aware of his innate ability and had taken precautions by using only spells instead but he could clearly tell that most of what he used were skills. That meant he already had multiple skills active before he had even stepped foot out of the castle.
Such a thing was ludicrous as even if passive skill were skills that were always active if one was to keep an active skill constantly active, they would continuously burn through their mana reserves, and even for a behemoth— demons who typically possess large amounts of mana— such a thing was insanely reckless and risky.