10 Smartest Anime Characters Of All Time
2. L Lawliet Cole - Death Note
Yes, Light did kill L. However, L is the more intelligent of the two.
The only reason Light was able to defeat L was because he had knowledge of Shinigami rules. If it weren't for that, L would have eventually stopped him, as Light's ego would have been his downfall, much like it was with Near.
You could argue L did beat Light, as the final nail in his coffin was Near. L knew that if there was a possibility he'd die, he'd need a contingency plan. Light on the other hand had no real backup plan in case he lost, as he never thought he could.
This ties in with L's incredible amount of to self-awareness. He does some truly awful things trying to catch Kira, but the difference between him and Light is that he knows he's a monster.
Instead of using the Death Note to enact change in the Japanese judicial system, Light uses it to feel like a god by punishing anyone he deems evil, and still thinks himself the good guy. He is such an egotist he's completely incapable of any introspection. L though knows his actions make him a bad person, viewing himself as a necessary evil rather than a hero.
The dumbest thing L did was find befriend Light. Who can blame him though? Everyone needs a friend - even the world's greatest detective.