What do you give to the man who has nothing but a few seconds left of life?
Light Yagami had, in his customary fashion, carefully considered his options.
L had been a thorn in his side, true. But he had been the only true match for Kira in the world. He had been a worthy opponent, and he had called Light his friend.
Had things gone differently--if a little black notebook had never caught Light's eye, if Light had just left it there on the ground, if Light had simply thrown it away without ever writing a name--it might have been true. All his life, Light had been as a god among mortals, his higher intelligence gone unquestioned among all who knew him. He had never had someone he could call his equal. He had never had someone he could even call an acquaintance. There were merely lesser beings who associated with him in hopes of getting something of him for themselves, praying that a bit of his intelligence would rub off on them, perhaps, or simply girls wanting to possess him and prove that they were worthy of the great Light Yagami.
L, on the other hand, was the first person Light had ever met who nearly matched him in intelligence.
Light had even feared, on occasion, that he might lose in their battle of wits.
Now, of course, the battle was soon to be over. Light had successfully maneuvered Rem into doing the only thing the foolish, overly-romantic shinigami could do. L would soon be dead, and he would be safe from any repercussions from Rem regarding how he treated Misa. Everything had fallen into place.
He had no delusions of being favored by any god. Light had never believed in any higher power. Even after being confronted with definitive proof of the supernatural and having a death-god for a companion, he hardly believed shinigami worthy of worship. Light knew: there was no Heaven, there was no Hell, there was no reincarnation, and the dead did not remain as family spirits.
There was no God.
Light intended to change that last fact.
He was the only one worthy of the title. All that he had done after picking up the Death Note he had done by his own ingenuity.
L had tried to stand in his way, and the only proper punishment for that was death.
Yet the soon-to-be-God was a gracious God. He would give his fallen enemy one final boon.
He had narrowed his options down to two:
Light could allow L to die in the presence of a friend, or he could allow L to die with the mystery solved, knowing that his suspicions had been right the entire time.
There was no way the first option would satisfy L. L was happy to have a friend in Light, true, but his true passion was and always had been in solving puzzles. He would never be satisfied to rest without knowing whether or not Light had truly been Kira.
Light's parting gift for L would be, simply, the truth.
So as L lay dying on the floor, Light stood over him... and smiled.
Light saw, for a fleeting instant, the realization dawning in L's eyes.
Then, slowly, the world-famous detective's eyes closed, and Light could almost feel as L slipped into the great nothingness.