Figuring out the best characters on BBC America's Orphan Black can be an interesting task. Since a majority of the people on the show are actually Leda clones all portrayed by Tatiana Maslany, they shared so many similarities but were still among the most unique characters anywhere on television.
The show's most pivotal clones (Sarah, Alison, Cosima, Beth, Helena, and Rachel) were all introduced during season 1, as were other key members of Clone Club (Art, Delphine, Scott, etc.). Still, the series managed to find ways to debut some of its best and most intriguing characters in season 2 and beyond, including new clones.
Virginia Coady
The majority of Orphan Black season 2 saw Rachel Duncan take on the role of the main antagonist. When she was put on the sidelines due to injury, the show needed a new villain and someone who stepped into the role was Virginia Coady (Krya Harper) but in a totally different way.
She was a doctor who was using the Castor disease to sterilize innocent civilian women. Coady also held Helena captive to experiment on her. The only good Coady ever did was act as a mom to the Castor boys but she ruined that by killing them. Though not a good person, she was a formidable villain.
Adele
At the end of season 3, Sarah left with Kira, Mrs. S, and Kendall to live off the grid but Felix chose not to go with them. While they were away, Felix looked into finding his birth family, feeling especially left out after finding out that Sarah was related to their foster family.
Felix met his biological sister Adele (Lauren Hammersley) and bonded with her before ever telling the rest of his family. Adele always meant well, was a good confidant for Felix, and even helped Donnie when he was in legal trouble. She did it all and didn't even dig too deep into asking questions.
Mark Rollins
The introduction of Mark Rollins (Ari Millen) was one of the more interesting ones as he appeared before the audience ever fully knew the truth about him. He first showed up as a member of the Proletheans and the boyfriend of another intriguing character, Gracie.
It was later revealed that Mark was actually an undercover Castor agent who genuinely loved Gracie. He ended up helping most of the Leda clones and seemed to have a good relationship with Gracie despite his sickness until they were killed in season 5.
Ethan Duncan
Although he wasn't part of season 1, one of the most important characters in the entire story was Ethan Duncan (Andrew Gillies). He's one of the first Leda scientists and Rachel's adoptive father, making him pivotal to her and every other clone in some way.
His return to the main storyline in season 2 allowed the lore to expand and helped lead to Cosima getting better from her sickness. Ethan had many faults but he legitimately loved Rachel and he even took his own life to prevent Dyad from getting his science.
Ferdinand Chevalier
There are some relationships that worked wonders in this show and then there are a few couples that fans never got behind. One of the bad ones was between Rachel Duncan and Ferdinand Chevalier (James Frain). These were two villains and things seemed to get violent often between these manipulative individuals.
Just because Ferdinand wasn't likable doesn't mean he was a bad character. In fact, he was one of the longest-running antagonists, popping up at major moments until the final season. He also worked with Clone Club in a few moments as allies before ultimately facing off with Mrs. S, where they killed each other.
Charlotte Bowles
Sarah's escape from Dyad in the season 2 finale was assisted by Marion, who asked Sarah to visit her the following day. When Sarah arrived there, she was greeted by Charlotte Bowles (Cynthia Galant), who was identical to herself when she was a child.
Charlotte turned out to be the last living Leda clone following years of failed attempts to make new ones. Charlotte becomes a member of the family of sorts, helping Rachel in season 3 and eventually getting adopted by Art. She played a huge part in Orphan Black: The Next Chapter.
Kendall Malone
The mystery of the identity of the Leda original was consistent throughout season 3. The reveal that it was Kendall Malone (Alison Steadman) as both the Leda and Castor original was a twist that nobody saw coming, especially with the addition that Kendall was also Mrs. S's mother.
That family connection was more than just a cool shock. It led to some hilarious scenes as Kendall bickered with her daughter and was hilariously rude to everyone in her path. The bond she formed with everyone, specifically Cosima, made her eventual death one of the show's more heartbreaking moments.
Veera "M.K." Suominen
Most of the show's characters first appeared on the series itself but Veera "M.K." Suominen (Tatiana Maslany) is a different story. She was first seen in the accompanying comic book to the show and then debuted in season 4. It turned out that she had a greater connection to the plot than most characters introduced late.
M.K. was shown in the season 4 premiere, which was mostly a flashback to Beth's life before the pilot and leading up to the Maggie Chen shooting. She had been helping Beth and the rest of the clones longer than anyone realized and then she saved Sarah's family from incoming Neolutionists. M.K. was smart but paranoid, yet still overcame some of her trust issues to help her sisters.
Cal Morrison
Sarah's singular focus at times in season 1 was getting back to her daughter Kira. Not much was ever said about who Kira's dad was other than a passing mention when Sarah confirms that it isn't Vic. At the start of season 2, that mystery was uncovered when Sarah went to Cal Morrison (Michael Huisman) for help.
He had no idea about Kira but as soon as he found out, he became a good father figure. Cal protected Kira at all costs, was flexible with Sarah, understanding that she had a lot going on, and he came through for Clone Club often. It's just a shame that he didn't return in later seasons.
Krystal Goderitch
By the time season 3 rolled around, it seemed like every major clone had been introduced. Of course, thanks to the likes of Krystal Goderitch (Maslany) and eventually M.K., that wasn't the case. Krystal was unlike any other notable clone on the show in that she never really became aware of her status as a clone.
Even when it was mentioned to her, she shrugged it off as a lie since she didn't think Sarah looked like her. Her scenes were always hilarious as she spoke her mind and was much more vain than her sisters. Plus, Krystal proved to be smartest than she let on, coming closer to secrets than anyone expected.