The Umbrella Academy season 2 completely changes how superpowers are obtained within the show's mythology. Based on the comic books by Gerard Way and Gabriel Ba, The Umbrella Academy is a unique superhero tale where even the origin of super-powered individuals defies genre convention. Although the exact mechanics remain a mystery, the extra-terrestrial known as Sir Reginald Hargreeves released a jar of strange firefly-like lights and on October 1st 1989, 43 women suddenly found themselves miraculously giving birth to children with powers. Reginald would later pick 7 of these kids to form his Umbrella Academy superhero group. This quirky origin story gave The Umbrella Academy a set limit of 43 characters with abilities.
In The Umbrella Academy's second season, the Hargreeves siblings take a trip back to the 1960s, each carving out a life of their own in the past. Suffering amnesia, Vanya is taken in by the Cooper family to live on their farm as a nanny, forming a strong bond with Harlan, the Coopers' autistic son. In "The Majestic 12," a distressed Harlan runs away from the house and drowns in a nearby lake, but by breathing those strange firefly lights into him, Vayna is able to revive the boy. Later in the season, Harlan exhibits the same superpowers as Vanya, and although she tries to take these abilities away, Harlan remains super-powered.
This revelation fundamentally changes the nature of The Umbrella Academy. Previously, the Netflix series was restricted to the original 43 superheroes created by Reginald Hargreeves - every character with abilities would be a spontaneously born 29-year-old. However, the events of season 2 prove that any of those 43 original babies can pass their abilities onto other people without losing their own powers in the process. Consequently, The Umbrella Academy season 3 can now feature super-powered characters of any age, and from any background, and is also free to introduce way more than just 43 of them.
As mentioned previously, the exact nature of Sir Reginald's fireflies remains unknown, leaving many questions about The Umbrella Academy's power transfer twist unanswered. Vanya gave Harlan powers unintentionally while under extreme stress, suggesting trauma is a possible trigger. Furthermore, the transfer could be unique to Vanya's sound manipulation, or something specific about Harlan could make him a viable recipient. But based purely on what The Umbrella Academy season 2 reveals, it does appear that any of the Hargreeves siblings can bestow their superpowers upon others.
This could have major ramifications in The Umbrella Academy season 3 and beyond, both for the Hargreeves family and within the show's wider mythology. Focusing on the main cast, transferring powers could be a game-changer. For example, Luther always protects (or tries to protect) those close to him - could this desire tempt Number One to pass on his super-strength, allowing a loved one to protect themselves instead? Similarly, some of Klaus cult members are bound to still be alive in the new 2019. Robert Sheehan's character might get drunk one night and gift all his followers the ability to commune with the dead. The Umbrella Academy season 2's Harlan twist opens up a raft of intriguing new possibilities for the Hargreeves siblings' powers.
The same can be said for the other super-powered individuals The Umbrella Academy has yet to introduce. Aside from the 7 Academy members and Lila, there are another 35 characters totally unaccounted for. It's possible that one of those mystery 1989 babies has already discovered that their powers can be transferred from person to person and is taking full advantage, either by selling superpowers for profit, or by building a loyal army of ability-users. The Umbrella Academy has always been a story where anything felt possible, but now that superpowers have spread beyond the original 43 children, season 3 looks even more unpredictable.