Kyubey is an idiot. real talk

Wikipedia said:
The Incubators developed the technology to convert emotions into energy, which they use to counter entropy and prevent the impending heat death of the universe. Having evaluated countless races throughout the universe, the Incubators find ideal subjects among humans, specifically pubescent and prepubescent girls as they produce the most energy which reaches its zenith when a magical girl's soul gem turns into a grief seed. Kyubey claims his race lacks emotions (or, at least, that those in his race who have emotions are abnormal), with little understanding of mortality or the value of life, considering their actions simply utilitarian in nature despite appearing cruel to others. Despite this, Kyubey is a very skilled manipulator as he leaves out the vital aspects of the contracts and only reveals the truth when asked. According to Kyubey, the very existence of the Magi-Witch system is what allowed the evolution of mankind's civilization, as many of the main events in human history have had magical girls involved. Despite answering all questions posed to him, there is still much about the universe that Kyubey has not spoken of.

PuellaMagiWiki said:
Kyubey is an Incubator, a member of an alien race dedicated to counteracting the effects of (and possibly negating) entropy: the principle that energy output is always less than energy input, a fact that is presently causing the universe to slowly die out. In order to achieve this, Kyubey collects raw energy from a source that seems to be excepted from entropy: the emotions of girls in their second growth stage (14-18). To harvest this energy, Kyubey forms contracts with teenage girls, trading one wish for their servitude as a Puella Magi, magical girls who use their powers to defeat the evil witches, who then drop grief seeds. The energy produced during this process is then harvested by Kyubey through unknown means. Kyubey does not reveal, however, that Puella Magi turn into witches after falling into despair, which are then fought by other Puella Magi, creating an endless cycle. Because of this, Kyubey is often seen as the true antagonist of the series, despite the fact that his justification is that he is saving countless other sectors of the universe in doing so. Kyubey's goal during the course of Madoka Magica is to turn Madoka into an incredibly powerful Puella Magi, who will then destroy Walpurgis Night and become the most powerful witch, Kriemhild Gretchen, a process which apparently produces obscene amounts of energy, at the expense of the human race (as there would be no Puella Magi able to defeat the most powerful witch).