The cast of hilarious and intriguing characters. There are many characters within the show who are fully developed and their personalities are clear, but the main characters in the show are the seven siblings in the Umbrella Academy and most everyone else is a side character.
There is a wide range of personalities represented within the show from characters committing villainous actions to characters having biting sarcasm and mean-spirited responses to characters providing comedic relief.
Reginald
Reginald is a villainous character of the series through his emotional abuse while raising all of the Umbrella Academy siblings. There are moments of sympathy about him that appear, but they're very fleeting and never clear enough to affect his character or the audience's hatred for him. In the second season, he also dismissed his adult children when they came to him for help, and instead of hearing them out and trying to understand them he targeted their weaknesses, specifically Luther and Diego, and broke them down yet again.
Luther
Luther is a somewhat boring character that doesn't have too much depth to him, especially in the first season. Luther grew up believing everything Reginald told them and following his every order without question, and this makes him a frustrating character as the audience is mostly disgusted at Reginald's parenting skills and most of his decisions and at first Luther just seems to be an extension of him.
Although Luther is trying to find his own identity apart from Reginald through most of season 2, and the audience wants to see him happy, it's difficult liking him when he's still so tied to Reginald.
The Handler
The Handler is a fantastic character within the series with her fashion choices and her role at The Commission. She always seems to be one step ahead of everyone, except for Five evenly matching her, and she destroys lives in a stylish way. She has a sarcastic and deadpan edge to her and she's an interesting character, although not the most likable as a lot of her actions end up hurting other main characters given her antagonist status.
Vanya
Vanya has had an extremely traumatic childhood as Reginald was afraid of her powers so he chose to make her feel unimportant and ordinary instead of continuing to work with her to control her powers. Once she learns the truth, she's understandably furious and loses control causing her to be villainous by the end of the first season. Vanya becomes softer in the second season as she forms a close relationship with a woman and her son when they're sent to the 1960s. Although she's a character to root for and most want to see her happy, she also might not be considered to be the most likable character of the series having moments where the audience felt bad for Vanya and moments where they hated her.
Five
Five is one of the most sarcastic and funny characters of the series, but he can also be mean-spirited and blunt even though it's clear that he does care about his family. Five garners a lot of sympathy but also some frustration given his personality and approach to getting his siblings to help him stop the apocalypse.
Five's rough edges are part of his personality that he's come into over the years being alone in the apocalypse and ing The Commission as a hitman. Given Five's complicated backstory, the personality makes sense, but it still makes him a little less likable overall.
Diego
Diego is a lovable but brooding character who has a tough exterior but has shown time and again that he truly cares about everyone around him especially his family even if he doesn't act like it all the time. He, like the rest of his siblings, had a difficult time growing up and his added frustration with working through a stutter while deeply caring for his mother Grace for helping him and hating Reginald for treating him and his siblings terribly makes him more relatable and likable.
Ben
Although everyone will have to see what kind of person Ben is as part of the Sparrow Academy in season 3, he is one of the most likable characters of the series. Ben cares deeply for his siblings and tries to protect from beyond the grave through Klaus. He fights to help them when he's needed and he's there to give Klaus advice even if he doesn't listen it's always good advice. The other siblings have had moments with Ben as Diego hugged him when he was possessing Klaus and he was able to communicate with Vanya; Ben's love and kindness is infectious.
Allison
Allison is an incredibly caring character who deeply cares for her daughter and her siblings and she constantly shows it. She wants everyone in the Umbrella Academy to be together and work together without letting the problems of the past get in their way. She cared for and tried to protect Vanya when no one else would. Although she's idealistic she is also realistic and is able to stand up for what she believes in and face things head-on making her a very likable character.
Klaus
Klaus is a fan-favorite character that tends to steal the show as he truly cares about his family and also has moments of depth and drama that make him extremely likable.