The following article contains spoilers from "Chapter One: Past" in The Flash: One-Minute War Special #1, on sale now.
The more that is learned about the Flash's new alien enemies, the Fraction, the more terrifying they become. Aside from being intergalactic parasites, "Chapter One: Past" from The Flash: One-Minute War Special #1 (by Jeremy Adams, Fernando Pasarin, Matt Ryan, Jason Paz, Matt Herms, and Rob Leigh) highlights how there is no limit as to where they can strike. The Speed Force technology they use has accelerated their technological progress to the point where they cannot sustain themselves on the resources of their native world alone, and their discovery of "organic conduits" makes them unique among other alien armies.
Their origin story revealed that when they find other speedsters across the universe, they capture them to power their ships. While their initial technological developments allowed them to use the Speed Force to travel quickly across the universe, it is the implementation of conduits that allow them access to different universes and different time periods. This offers an explanation as to why the Fraction are such an imposing threat: There is nowhere in space and time that is beyond their reach.
The Villains of "One-Minute War" Can Attack Anywhere at Any Time
The Fraction do not possess a natural connection to the Speed Force's power. Rather, they use technology to siphon power from it, greatly increasing their own speed. This however, is the only gift of the Speed Force they can acquire with their technology. Simply put, they have super-speed, but no capacity to travel across time or through different dimensions without stealing a natural speedster's abilities.
So, when they discover a world with a speedster of its own, the priority is to capture them alive. The Fraction's entre motive is to harvest the natural resources of any planet they invade to sustain their own dwindling empire, so they need to constantly raid other worlds just to keep it going. Having a living battery that can transport them across time and space creates a virtually endless opportunity for them to steal the resources they need.
The Incalculable Damage Caused by the Fraction
There is evidence to support that the Fraction has already used other speedsters to enable more invasions across time and space. In The Flash #784 (by Jeremy Adams, Amancay Nahuelpan, Jeromy Cox, Rob Leigh), Max Mercury and Jesse Quick ended up on an alternate world where the Fraction had arrived ten years prior and left the Earth barren. This wasn't some alternate history where things went horribly wrong, these were the actions of the same Fraction the Flash Family is fighting today.
The revelation that they have been raiding different points in history and even different universes suddenly paints the Fraction in a new light. It was always assumed they were an especially dangerous breed of invaders because they were powered by the Speed Force. An entre army that can move as fast as the Flash is a terrifying thought, but they are so much more than just speed. By using other speedsters, the Fraction can access the most dangerous abilities the Speed Force can grant, and they have been gleefully abusing that power to further their conquests. There is no telling how many worlds their greed has ruined, but the Flash and his allies are not the first speedsters the Fraction have bested, and if they fall here, then they will be used as instruments of further conquest as well.