Based on the Dark Horse comic book line created by Gerard Way, the Umbrella Academy focuses on a dysfunctional family of heroes who must put aside their differences and save the world.
The original comics contained very different material from what would be typically seen from other comics.
The Netflix adaptation made some changes to those genre-defying norms to create a more grounded show.
But what exactly did they change?
POWERS

Out the gate, some characters have very different powers in the comics.
Diego’s knife skills remain top-notch, but in the comic he is capable of surviving underwater for long periods of time and hasn’t shown the telekinetic bent that was seen in season 2.
Klaus’s powers are also quite different in the comics. While he does still have immortality and the power to communicate with the dead in the comics, he also possesses the powers of telekinesis, flight, astral projection and telepathy (airwave communication). Another small detail in the comics is that he isn’t able to fully harness his powers while wearing shoes so he tends to walk around barefooted.
Luther’s power in the show is super strength, which is even further enhanced when his father uses a serum based on Pogo’s blood to heal him. In the comics however, his head is attached to a martian gorilla which then allows him to use the abilities of one.
Allison’s power to change the minds of people around her is based on her comic ability to warp reality. A hint of this power was seen in the premiere of season 2 but, since then, it sadly has been nowhere to be found.
HAZEL AND CHA-CHA

The version of Hazel and Cha-Cha presented by the comics do not adhere closely to their live-action counterparts.
The comic book versions of these iconic assassins are brutal and psychopathic in their relentless pursuit of the Umbrella Academy, silent and ruthless to the point of absurdity.
In the show, Hazel and Cha-Cha are portrayed as blue-collar workers, still brutal and relentless but much more human. They’re frequently at odds with The Commission as their superiors seem intent on cutting their budget at every turn as they demand more from them.
Hazel, in particular, is shown to be more merciful. It is revealed that he spared the life of a witness to one of his targets and his relationship with Agnes is the primary reason he quits The Commission.
The Swedes (another original creation of the show) take up the role of silent, psychopathic assassins in season two.
KLAUS AND VANYA

Many aspects of Klaus and Vanya were retooled for the express purposes of the show.
Their sexuality isn’t a part of their characterization but it was introduced later as their characters were developed.
Klaus’s relationship with Ben (his dead brother) isn’t even a factor in the comics and all of their shenanigans in the show are completely original. The cult he creates in season 2 is another original idea of the show.
Vanya’s relationships in the show are also original. In the comics, Diego had a thing for her which, thankfully, was changed to create a more interesting sibling dynamic. Her amnesia was pulled directly from the comics but Five shooting her in the head, her subsequent paralysis, and recovery were left in the comics.
FIVE

Our favorite time traveling assassin is also quite different in the comics.
Aiden Gallagher plays Five brilliantly in the Netflix show, combining his youth with the burdened and cynical demeanor of an elderly man who has seen too much and done too much.
In the comics, Five’s story is much darker.
His attempt to escape the apocalypse result in his kidnapping by the Temps Aeternalis (The Commission in the show) where he is tortured and implanted with the DNA of several serial killers to make him a perfect killer. He is stuck in the body of a ten-year-old when he escapes and he indulges in drugs and alcohol and other incredibly risqué behaviour
LEONARD PEABODY (THE CONDUCTOR)

Vanya’s love interest in season 1 features a rather drastic change from the comics.
Leonard Peabody (played by John Magaro) was also born on the same day as the children that become the Umbrella Academy but only by coincidence. Growing up in an abusive household, Leonard grows up obsessing about the Umbrella Academy and inserts himself into Vanya’s life as a violin student. His manipulation draws out Vanya’s powers but it also breaks her mental psyche.
In the comics, Vanya is manipulated by a being called The Conductor, head of the Orchestra Verdammten. The orchestra is basically a cult of violinists that seeks to cause the end of the world using Vanya.
In both the comics and the series, Vanya kills her oppressors.
OTHER ORIGINAL CHARACTERS

The show also introduces some other original characters to flesh out their story and improve characters.
The Handler (played by Kate Walsh) serves as the primary antagonist for the first two seasons of the Umbrella Academy.
Lila (played by Ritu Arya) is another member of the Commission, Diego’s love interest in season 2 and is revealed to be one of the 43 children born on the same day as the other members of the Umbrella Academy.
Sissy (played by Marin Ireland) and her family are introduced in season 2 and give Vanya the semblance of normalcy that her father indoctrinated into her but Sissy and Vanya discover a romantic connection.
Raymond Chestnut (played by Yusuf Gatewood) is another original character introduced in season 2. His marriage to Allison and his involvement with the civil rights movement also further Allison’s development.
CONCLUSION

On the whole, the changes made to the Umbrella Academy Netflix adaptation are positive, creating a more human element for viewers to interact with. With season 3 on track, we can’t wait to see what the next chapter has in store for this family.