The Umbrella Academy season 2 introduced a slew of new superpowered characters, including perhaps its most mysterious and consequential addition, Harlan Cooper, a boy central to Vanya's storyline and redemption arc. Just how Harlan received his abilities will likely factor into the series' story arcs and eventual endgame.
After The Umbrella Academy's season 1 ending, season 2's opening episode sees the dysfunctional Vanya saves Harlan with her powers, seemingly transferring some energy into him. Was it this interaction that led to the manifestation of Harlan's similar powers later in the season?
The answer to that question seems to be yes, at least according to series showrunner Steven Blackman and actor Ellen Page. In an interview with Vanya's comic book counterpart, who has been largely sidelined after her defeat, Blackman and company seem to be paving a way for the character's continued importance throughout the remainder of the Netflix series, including the setup for what is to come. And from what has been hinted, much of that Harlan-centric payoff may be just around the corner.
Despite Vanya's attempt remove the explosive force from Harlan, who struggled to contain it in the season 2 finale, a final shot of the child - levitating a wooden bird telekinetically - reveals that there may be some residual powers remaining. Many have speculated that the bird could foreshadow the formation of the Sparrow Academy (the alternate universe replacement of the Umbrella Academy in the new timeline, also formed by Sir Reginald), which will surely for much of season 3's developments, tying Vanya's actions to the new alternate universe in which the Hargreeves siblings find themselves.
But Vanya isn't the only one rumored to be responsible for power manifestation. With confirmation of Sir Reginald and his children (namely, Vanya, who he tortured and isolated throughout her childhood), would not be out of the question and might help to bring the Vanya storyline full-circle in future chapters.
Harlan Cooper, a character absent from the source material, was one of the more mysterious additions to The Umbrella Academy's season 2 lineup. It would be odd for the character to be discarded after the care taken to establish him as such an important figure in Vanya's life and story. After her dramatic heel-turn last season, Harlan - whom she literally breathes the life back into - is an embodiment of Vanya's capacity and desire for good. Yet, with season 3 presumably set fifty-six years in Harlan's future, just how he will tie into Vanya's story and the series' future, much like this superpowered kid, remains a mystery.