|“||It's not just the notebook I'm after. I wanna eliminate my competition. I will be the best. I don't care what it takes. I'll beat Near by any means necessary.||„|
Mello has blonde hair and blue eyes. He later gains a large scar on the left side of his face, after initiating an explosion of the mafia hideout in order to escape being captured. Mello is usually seen wearing dark leather clothes. The manga depicts him wearing a red colored rosary and a cross-adorned bracelet. In the anime however, the cross has been edited to be a stick (the horizontal portion of the would-be-cross in not present). He also carries a gun that, in the manga, has a cross attached to a chain that hangs from its handle.
While Mello is certainly a genius and more intelligent than most people, the concept of being only the second most intelligent person in Wammy's, behind Near, fuels the inferiority complex that defines Mello's character. Mello verges on being immoral in his obsession with being the one to take down Kira and is willing to do "whatever it takes". Tactics which include kidnapping Director of the Japanese Police's daughter (Sayu Yagami), and having a member of the mafia write down most of the SPK member's names in Sidoh's Death Note. In the manga, after Mello has successfully stolen a Death Note, he even goes so far as to attempt to blackmail the President of the United States via telephone into giving him funds and resources to aid his hunt for Kira, threatening that if his demands are not met he will use the Death Note to force the president to launch the United States' nuclear missiles and start World War III. Arguably, Mello isn't even trying to defeat Kira out of a sense of "justice", but 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 simply runner-up to Near, or as Mello describes his goal in his own words, "I will be the new Number One!"
The artist of Death Note, Takeshi Obata points out in the book Death Note: How To Read 13 that Mello's envy and hatred of Near was only one-way, and that Near "honestly liked Mello". The book states that Mello isn't purely evil, citing his apology and genuine care for Matt's well-being, as well as earlier in the series when he apologizes to Soichiro Yagami. It also states that Mello has an excellent mind and that he sometimes lets his emotions get in his way. Tsugumi Ohba, the writer of Death Note, stated that Mello works hard for everything.
Similar to L's fondness for sweets, Mello often eats bars of chocolate, even when talking. In the manga, Mello is often seen licking the chocolate before eating it. Mello also has a habit of bending his right leg up while sitting, often with his left leg turned outwards. He tends to alternate between that pose and simply crossing his right leg over his left leg. Another thing about him that is very like L is his tendency to take drastic strategies to confuse and force the hand of his opponents.