Warning: Um, slight hints of yaoi, I guess, if you want to interpret it that way.
Kira is the Evil that Hydes in the Light
Kira had always been there, with light, inside his mind, watching, waiting, hiding. No one knew Kira was there, the evil hiding in the light, not even the light knew. The Death Note was the potion that separated Jekyll and Hyde, so Kira tricked him, he tricked light, manipulated him into killing 'bad people' but really Kira didn't care, he just had to satisfy his blood lust, by the time light realized what he was doing was wrong, it was too late, Kira took over.
Then light met L, he had something to fight for again. He tried to trick Kira into giving up the Death Note, and he did, but Kira was just too smart, he got it back.
Kira killed L, not light, never light, not his beloved L, not anyone, Kira killed L, and light died too, light couldn't be without L, without justice.
But part of light remained, fighting, Kira didn't notice, he thought he'd won, but L lived on in his successors, and if L had lived, so had light, and then Kira lost, light won, for light would always win, justice will always conquer evil in the end, or beyond the end, because L's death was the end, but light still won because light would always win, even after what Kira for all his smarts thought was the end, but it wasn't the end, because justice could never end, and after all, justice was L, L was justice, and justice was light, always fighting the dark, always winning.
Kira was just too bad to realize what L had known all along, "Justice will prevail, no matter what," Kira had been fighting a losing battle, even as the world thought he was winning.
light watched as Kira died, standing with L, he witnessed what had been bound to happen, and light cried, not for Kira, but for those who loved him, because everyone, no matter how evil, had someone who loved him, and Misa no matter her faults, didn't deserve this. But that was what death was, someone being hurt, that was probably why Kira liked death so much.
I didn't capitalize light on purpose, in case you were wondering... So, um tell me what you think.