Even though Fred can easily be mistaken as a child, he’s an essential part of Moriarty’s plans. He serves as Moriarty’s informant as well as contact person, and his martial arts skills also make him a good bodyguard and henchman. These traits, however, are only good enough for him to belong to the group. After all, Moriarty’s entourage includes extremely skilled individuals.

What makes Fred stand out is the way the 2nd Cours further probed his character. We get to see his empathy and morals when he refused to let a single child die in The Hunting Of The Baskervilles despite Louis’ objection. Another instance is when he helped Louis contact Sherlock in order to ask him to save William.

Adam Whiteley has a short but impactful appearance in the show. When he’s first introduced into the series, he poses a big question mark. He seems to be a good guy, but it’s not entirely clear whether or not he’s on Moriarty’s side. As the story unfolds, his character only proves to be quite important, especially as a politician whose public support continues to increase. His sudden rise, however, also comes to an abrupt end due to Milverton’s influence. Milverton smeared and toyed with Whiteley to the point of no return. Even in death, Whiteley still leaves a strong impression as his last breath served as Moriarty’s podium to introduce himself as the one pulling the strings in the shadows.

Milverton’s character is first introduced with a mist of mystery, but viewers are certain that he’s up to no good the moment they’ve laid their eyes on him. True enough, Milverton’s character panned out as the greatest blackmailer. With his connections and status, he easily gains information to blackmail others. This is how he managed to toy with Whiteley with ease. Milverton is one of the few inherently evil major characters in the series, and he proves this by taking pleasure in watching others suffer.

Partnered with his wit and intellect, Milverton proves to be a force to be reckoned with. He even manages to set a stage for Moriarty and Sherlock to face each other as he gets front seat rights, but his overconfidence becomes his downfall. He misjudges Sherlock and Moriarty, which leads to his death. If his character has been explored further, Milverton would deserve a higher spot on this list. Nevertheless, his exploits serve to further develop Sherlock and Moriarty’s characters and also hasten Moriarty’s grand plan.

Dominating the initial episodes of the 2nd Cours, Irene Adler showed us that she’s one hell of a woman. Her disguise manages to leave Sherlock clueless, and she even manages to lead him by the nose. Sherlock, of course, eventually manages to figure everything out, but the mere fact she managed to one-up Sherlock is a feat to behold. Her biggest feat, however, isn’t that. That’s merely an opening act to the slew of achievements she is to accomplish.

The moment she resigns her identity as Irene Adler and assumes the identity of James Bonde, her character develops exponentially. He willingly devotes himself as Moriarty’s pawn and does whatever he bids him to do, but it’s quite notable that his character also blurred into the sideline after assuming his new identity.

The 1st Cours highlighted William’s skills and intellect and rightly so. After all, the series tackles the already known story in a new light. The 2nd Cours, however, does a good job showcasing the depth of the other two Moriartys. Albert is shown as someone who can hold his ground and contribute a big part to their cause without detailed instructions. By infiltrating the military ranks, he’s the one who managed to recruit Irene Adler into their group.

Louis is initially shown as a stiff character that follows William’s orders to a T. As the story progresses, however, his character becomes more well-rounded while maintaining his uniqueness. His character truly shines when partnered with Fred. When Fred goes out of their way to save a child, Louis adamantly tries to stop him. He can come off as coldhearted, but eventually shows his soft side when William’s life is the one at stake. Partnered again with Fred, he contacted Sherlock to ask his help to save his brother, which perfectly shows the duality of his character.