For one such as him, one who is perfect, who is adored, who is God, the idea of being wrong or at a loss simply didn't seem fathomable. After he'd found the Death Note and started his cleansing of the world, Yagami Light had come into the biggest obstacle he had ever faced in anything and it went by the name L.
The man countered and challenged him at every single turn and there had been times in their complex game of cat and mouse where he realized he had gotten through certain circumstances by a very small margin. L was a positively brilliant man behind all his eccentricities and it was sheer luck tipped in his favor that had kept his neck out of the proverbial noose on more than a few occasions. Light, however, balanced the detective's absolute brilliance with the ability to manipulate people that had been brought to the surface upon claiming the Death Note for his own. He had a silver tongue and superb acting skills that he could bring to the fore with hardly any thought at all.
He hadn't realized how much he truly enjoyed the other man's company in all the time they spent together. The raven-haired detective was quirky and blunt and aggravating but he was also intelligent beyond even Light's own faculties and the young man always – begrudgingly – felt exhilarated when he and L would get into their many verbal – and physical – spars.
There was a part of him that never truly believed he would ever win against L, the world's three best detectives in one untidy package. The small bit of him that was still truly Yagami Light and not Kira was fine with losing to L. He'd realized it all when he had given up ownership of the Death Note and lost all his memories of being the serial killer. The Light of Before didn't really mind losing to Ryuuzaki because the man was his only competition and he was brilliant and there was absolutely no shame in losing to someone like him. He hadn't felt bitter or resentful when L would outsmart him in their witty banter.
Of course once he remembered who he was, remembered that he was a God, any feelings of affection for the man had been lost to the wayside and gleefully tossed into the farthest and darkest corner of his mind. There was no place in his plans as the world's savior for friendship and certainly not with the one man who could put him in prison for life or have him sentenced to the death penalty for mass homicide. The more he thought about it and stewed over his one true obstacle, the more he was able to re-convince himself that Ryuuzaki needed to die, L needed to die.
It was almost pathetically easy manipulating Rem into writing the man's name in her notebook. That a shinigami would so willingly risk its existence for the sake of a mere human being – and one like Amane Misa at that – was all the proof his Death-Note-twisted mind needed to be convinced that feelings were a sign of the weak and he was a God and Gods are not weak.
Watching L die, seeing his greatest nemesis and the only person truly capable of being his friend, tip out of his chair and knowing his heart was stopping in his chest seemed like a dream to Light. He'd wanted it, ached for it and craved for it, for what felt like eons and it was truly unexceptional how easily the world's greatest sleuth slipped from the land of the living.
For all his planning and brilliance, Light hadn't thought about how he would feel – convinced as he was that he couldn't feel because he was a God – watching such a remarkable man die such an unremarkable death. He hadn't counted on feeling an ounce of guilt or remorse, hadn't planned on feeling as if he had cheated such an incredible man out of a death worthy of him, hadn't considered feeling as though he had stolen one of the very few truly good things in the world away from mankind.
It wasn't until the man's funeral – which, sickeningly, was just as nondescript as his death – that Yagami Light of Before actually realized what he'd done. The infamous L was gone, the only sign that he'd lived was a small tombstone with the name Ryuuzaki carved into its surface and the only people that came to show their respect to the deceased man were the members of the Task Force. There was no family for the eccentric detective, no loved ones to shed tears over the snuffing of his life far too early and the only friend the man ever had was the one that had killed him.
The realization of the horrible things he had done hit him full force once the few others at the funeral had left and Light of Before was left in the wake of Kira's destruction, left to deal with the fact that he was able to live his life any way he wanted to simply because he'd taken the life of one far more deserving of the years.
He couldn't remember the last time he'd cried – truly cried – for anything and yet he would never forget the way his heart had twisted inside his chest as he read and re-read the engraving on the dark gray stone and fell to his knees before it, silent tears trickling from his eyes. There was only a single word to mark the passing of an extraordinary person and it wasn't even the man's real name. Due to the absence of loved ones or next of kin, there weren't even the customary sentiments on the tombstone, just that one word, just the name Ryuuzaki to make his mark.
In that moment, the only thing Light could ask for was his own death despite the fact that the world had been laid at his feet. He had the opportunity of a lifetime paid for with the blood of others and all he could think of was dying himself in the hopes that somehow he could be given a chance to redeem himself to the one person he'd ever truly felt close to.