L has always been very afraid of losing his sanity, and it would hurt him terribly. Would this be all right for the event?

He'd start writing nonsense on his walls, hearing voices, and experiencing delusions, many of them having to do with the Kira investigation. He'd gain motivation and become enthusiastic to the point of euphoria, only to be backed into a corner when he learns how little sense he's actually making. It would be hell on him to realize that he's lost his mind, since L's genius and logical abilities are such an integral part of his character.