Mello - Death Note.

(Indication code: DG5DEZ)
Although Mello is certainly a genius and more intelligent than most people, the fact that he is only the second most intelligent person in Wammy's House, behind Near, fuels the inferiority complex that defines his character. Mello borders on immorality in his obsession with being the only one to defeat Kira and is willing to do "anything," including kidnapping Sayu Yagami, the daughter of the Japanese Police Director, and orchestrating the assassinations of most of the SPK members. In the manga, after successfully stealing a Death Note, Mello goes so far as to try to blackmail the President of the United States to obtain funds and resources to help him in the search for Kira and to escape Near, threatening to use the Death Note to force the president to launch the United States' nuclear missiles and start World War III. One could argue that Mello isn't trying to defeat Kira out of a sense of "justice," but rather because capturing Kira will prove to the world that Mello is indeed the worthy successor to L as the world's greatest detective, and not just a mere sidekick to Near. As Mello describes his goal in his own words: "I will become number one!"

The book states that Mello's envy and hatred for Near are one-sided and that Near "sincerely liked Mello." It asserts that Mello is not purely evil, citing his genuine concern for Matt's well-being and his apology for Matt's death, as well as his apology to Soichiro Yagami for his responsibility in inflicting Soichiro's fatal injuries. The book also states that Mello has a brilliant mind and that he sometimes lets his emotions interfere. Tsugumi Ohba, the screenwriter of Death Note, stated that Mello strives hard to achieve everything, unlike Near, whose intellectual gifts are natural.
Just as L has a fondness for sweets, Mello is seen eating only chocolate bars, even while talking. In the manga, he is seen licking the chocolate before...