As the screens flashed red, he felt a twinge of in a part of himself he'd thought was numb. He blinked. Was that… remorse?
Something Light had accepted from the beginning, from the moment his pen had first touched the notes' pages, was the fact he could not over analyze. To be an idealist… No. To be the Ideal, one cannot dwell in shades of grey. There can be no doubt. Justice is black and white, and Kira must be blind to all else.
Somehow, however, he had failed. Having wiped away the memories and for a time the demanding role of universal judge and executioner, he felt something he'd never anticipated. He was happy fighting on the side of the law, beside his father, beside Ryuuzaki…only to realize he was the monster he'd sought to destroy.
While Ryuuzaki had written off his scream as the surprise of seeing a real shinigami, he had a much harder time convincing himself that his cry wasn't out of some sense of betrayal.
He realized something then. What had started as Light Yagami's quest for a new and better world had grown into something so much larger. While Kira had started as merely an expression of Light's will, Light was no longer Kira.
Light's moral outrage and pure prospective, still fresh in his mind despite the cloud of his recovered purpose, was too clear a barometer.
He could no longer pretend to be both, that wouldn't do. From now on he would either always be Light or always be Kira. There was no compromise. Between the world in need of a savior and the unworthy begging to be slaughtered, he could see nothing else. One must die so the other could live.
He realized there was no way to stop the actions he'd set in place.
He looked at the back of Ryuuzaki's head and found himself torn between the two people he saw there: his best friend and his arch nemesis. As the man began to crumple before him, he wondered if the distinction really made a difference anymore.
As Kira moved to the dying L's side, his memory drifted back to a line of prose from the Literature class that now felt so ancient and insignificant; "I am in blood stepped in so far that, should I wade no more, returning were as tedious as go o'er."