Based on the comic book series by Gerard Way and Gabriel Bá, The Umbrella Academy season 1 featured a once revered team of superheroes and an extremely dysfunctional family coming together.
In many respects, Reginald Hargreeves is The Umbrella Academy’s greatest and true villain. Now in the wake of that, The Umbrella Academy season 3 could see them finally address their upbringing and the source of their problems more directly.
In the wake of his bitter disappointment with how The Umbrella Academy turned out, he could have become even more strict and cruel to mold them to his liking and without the two kindest souls as a buffer (Grace and Pogo) it could have been worse.
Rather than the Sparrow Academy, The Umbrella Academy could face dark images of themselves in a mirror. They could see how worse things could have been, as well as how strong the survivors they both are.
A doppelgangers story could serve as a literal manifestation of facing and defeating the darkest and most damaged parts of oneself. Not to mention, they could forcibly escape their father’s shadow at The Umbrella Academy.
By defeating the versions of themselves that he wanted them to be, and coming out of The Umbrella Academy season 3 even stronger for that would be an interesting twist. Also, who wouldn’t want to see an evil version of Klaus?