The following contains spoilers for The Umbrella Academy Season 3, now streaming on Netflix.
The Umbrella Academy Season 3 might have a terrifying world-ending event that the Sparrows are freaking out over, but it's just another day for the Umbrellas. The Kugelblitz grows bigger and stronger as each day passes in Season 3 of the Netflix series, and it's the most dangerous threat the Umbrellas have faced yet. But what exactly is it?
The Kugelblitz first takes shape in the Season 3 premiere "Meet the Family" after the Umbrellas arrive to the present day Sparrow Academy from 1963. Grace (the Sparrows' robotic servant) is the first one to find the red ball of doom in the Academy's basement and sees it as an act of God. Season 3, Episode 4, "Kugelblitz" actually dives into the phenomenon of the mysterious black hole, but curious minds must understand what a Grandfather Paradox is first.
What Is a Grandfather Paradox?
With a brand new wardrobe and retired mindset, Five theorizes that the Umbrellas didn't travel to another timeline; Reginald changed the current timeline. Reginald tells the Umbrellas that he didn't adopt them, seeing how disappointing they were when they met him in 1963. Five warns the others that their doppelgängers (a cheeky nod to Marvel's variants) are out there somewhere and they should avoid them. But it's later revealed that an adult Harlan (the boy Viktor gave powers to in Season 2) accidentally killed all the Umbrellas' mothers on October 1, 1989 -- which means the Umbrellas were never born.
From there, everything starts going awry because the Umbrellas are in a timeline they're never meant to exist in. Five calls this the Grandfather Paradox and an instructional video created by the Commission in Season 3, Episode 3, "Pocket Full of Lightning" helps understand the concept. In essence, the video proves that because the Umbrellas went back in time to 1963 and altered a lot of set-in-stone events (the most important being Harlan getting powers and the siblings meeting Reginald), they indirectly changed the timeline so that they were never born.
What Is a Kugelblitz?
The Kugelblitz is the deadly effect of the Grandfather Paradox. An "extra kinky kind of black hole," as Five calls it, the Kugelblitz releases waves of destruction to end the universe. At first the "Kugel waves" take out animals, but slowly destroy buildings and humans until it's just the super-powered beings and the Hotel Obsidian left. If someone were to get to close to the vortex, it would instantly vaporize them -- like Marcus.
To destroy the Kugelblitz, the Umbrellas and remaining Sparrows form a force field around it to condense it into Christopher, the floating cube. However, it subsequently explodes out of Christopher, killing him and Fei in the process. At this point, the Kugelblitz has won and the universe will end. But Reginald believes they can reset the universe by going through another dimension in Hotel Obsidian.
The group does successfully reset the timeline, but at a grave cost. The Umbrellas don't have their powers and Sloane is missing -- as if she doesn't exist in this new timeline. The Umbrella Academy Season 3's ending scene reveals that Reginald's true intention was never to prevent the apocalypse -- but to bring back his wife. Truthfully, the Umbrellas didn't defeat the Kugelblitz, but they did manage to make it out alive. Maybe they should just take what they can get and try not to mess up the timeline anymore.
All ten episodes of The Umbrella Academy Season 3 are now streaming on Netflix.