A Different Death Note Character Could Have Come Out On Top In The End
A thriller both psychological and supernatural, "Death Note" is a cat and mouse game, but the players change throughout the story. For the bulk of the series, it's a match between Light Yagami, the Death Note's owner who uses it to kill the world's criminals, and L, the world's greatest (and weirdest) detective who is determined to identify "Kira," the person responsible for the string of mysterious deaths.
L comes close to the truth several times, but Light manages to stay one step ahead. Part 1 of the series concludes with L's death; Light manipulated events so it wasn't even him who had to write L's name in the Death Note. However, Light's victory isn't permanent. L's two handpicked successors, Near and Mello, take over the Kira case. Like L, the two were raised in British orphanage Wammy's House. Mello also has a bitter, one-sided rivalry with Near.
Near works with the law while Mello, determined to prove himself the superior detective, joins the criminal underworld for a rule-breaking investigation. According to Tsugumi Ohba, author of the "Death Note" manga, it took him to the last second to decide which of L's successors would claim victory.
Death Note's twisty ending
Mello enters the story by kidnapping Japanese police director, Kanichi Takimura, and offering to trade him for the Death Note. When that fails, he and his mob associates next grab Sayu, Light's sister (and more importantly, daughter of Soichiro Yagami, the Kira Task Force's leader). The trade goes off and soon Mello is visited by the Shinigami Sidoh, who tells him of the Death Note's rules. When the authorities find Mello, he fakes his death in an explosion (but gets a nasty scar in the process).
After further investigation (aided by Halle Lidner, a member of Near's Special Provision for Kira) and exchanging information with his rival, Mello kidnaps broadcaster Kiyomi Takada, the "Voice of Kira." She kills Mello with a page from the Death Note, while Light in turn kills her by writing her name on a piece of Death Note paper. However, Mello's death is not in vain. Light's other accomplice, Teru Mikami, takes initiative and writes Takada's name in the Death Note itself. SPK agent Stephen Gevanni, who was trailing Mikami, finds the Note thanks to this. Near's team is able to switch the Death Note with a fake then catch Light and Mikami in a trap.
Near emerges the ultimate victor by unmasking Kira, but acknowledges he only did so through the help (and sacrifice) of Mello. Near concludes that it took the two of them combining forces to equal L.
Tsugumi Ohba's creative process
Interviewed for the encylopedia, "Death Note: How To Read 13," Ohba discussed how he devised the story's ending. For one, "[he] didn't want Light to lose because of a total mistake on his part," hence why it's Mikami's mistake that does in Kira. He also admits that part of him wanted Mello to be the one who defeated Light, not Near.
"I didn't decide on [Mello's role] until the last second. After Sidoh returned to the Shinigami realm, there was a period in which I struggled over what to do with Mello. After L's death, the idea that Mello would be the character to defeat Light was really strong in my mind. I figured that since Near was the best at Wammy's House, it would be more interesting if Mello were the final victor instead."
Even while writing a story about men gaining the power of god, Ohba was rooting for the underdog. However, he also explained why he decided against Mello coming out on top.
"[Mello] learned too much about the notebook early on, so I had to fade him out to sustain the intensity of the story... Because of this, I wasn't able to give him a large role at the end and instead switched it to him hurting Light indirectly. That's why his end was very plain, depicted in only one panel. I thought if he died too dramatically, the truth behind his death would be revealed."
In other words, Ohba sacrificed his affection for one character to the larger story's benefit — a very Light Yagami move.