Aion
Time-Traveller
Because Light was fully developed in the very first episode. The only thing he needed to come to terms with was the weight of killing another, and he quickly got over his feelings of fear once he started. What development did Light need? He viewed others as inferior to him and viewed himself above them - that was what made the story. The only possible development for him would've been the flashback kind, and showing overly dramatic images of him being abused in an effort to explain his thinking and make him sympathetic would've ruined him; one of the most 'evil' (I prefer to think of him as selfish - I view no-one as evil) characters in history.
Revy, on the other hand, has plenty of room for improvement. Rock's there to bring out her emotions and make her into a normal, less kill happy woman, in the long run at least. Yet, in the first two seasons, all she did was run around killing and give some vague reasons for why she turned out like she did during he few short conversations she shared with Rock. She's still the same person she was at the start, and that's because Black Lagoon is an action series and not a well-written drama where a person changes over time.
Revy, on the other hand, has plenty of room for improvement. Rock's there to bring out her emotions and make her into a normal, less kill happy woman, in the long run at least. Yet, in the first two seasons, all she did was run around killing and give some vague reasons for why she turned out like she did during he few short conversations she shared with Rock. She's still the same person she was at the start, and that's because Black Lagoon is an action series and not a well-written drama where a person changes over time.