The entire DC Universe might be safe from the onslaught of the latest Flash villain, Paradox, but that doesn't mean the danger has let up just yet, not even for his Rogues' Gallery! The Flash has proven to be one of the most important characters in the entire DC Universe, bringing to life the concept of the Multiverse and the Speed Force, both of which allow for myriad versions of DC's characters. His latest, most powerful villain, Paradox, has not only fully merged with the Speed Force --- rendering him nigh unstoppable --- but has also been busy trying to wipe The Flash from the entire multiverse --- and from existence, and has managed to take out some of The Flash's most formidable enemies as well.
In the pages of The Flash #755, Paradox is finally defeated, after a multiverse-spanning battle. Having been transported to the nether-realm in which Paradox resided --- a void outside the multiverse, wherein all points of time could be accessed --- The Flash soon found himself racing against time to stay one step ahead of Paradox, who had, at this point, killed his past self, thus creating the ultimate paradox and gaining near-godlike powers.
Along for the battle was Reverse-Flash, Eobard Thawne, who had been recruited from the future by the Flash himself, and who possessed the Lightning Rod, the only weapon known to defeat Paradox. Having been thwarted by Barry from killing Paradox in the past, before he'd gained his powers, the two former enemies had to team up to find a less fatal solution. Trapped in this battle was also former-villain Godspeed, August Heart, who had been trapped on a Cosmic Treadmill and used by Paradox to travel to various universes.
The issue ends with Reverse-Flash using his negative Speed Force energy to travel back to Paradox's formative moment, the instant in which he'd gained his powers and become obsessed with destroying the Flash while witnessing a battle between Flash and the Turtle. Rather than kill the man, as was his initial plan, Reverse-Flash instead imbues him with the inspiration to remain with his family, rather than focus on the unfolding battle. Having no reason to turn to evil, Paradox, in his present state, begins to fade from reality, his nether-realm dissolving with him. Only with the combined speed-force energy of the Flash, Godspeed, and Reverse-Flash do the trio escape to present-day Central City.
With the danger abated, the trio begin to make their separate ways. The Flash reunites with Iris, who believed Barry to be dead during the entire ordeal with Paradox. In his distraction, Godspeed confronts Reverse-Flash, who taunts the duo by lamenting how his defeat of Paradox should garner him some trust; knowing he's from the future, Godspeed uses this moment to ask Reverse-Flash if he knows who killed his brother, the impetus for Godspeed becoming a vigilante. Grabbing Godspeed, Reverse-Flash, with a snarl, responds, "Oh, that was me. I did it." and snaps Godspeed's neck!
In a shocking moment, Reverse-Flash ruthlessly snaps Godspeed's neck in a full-page splash, and races off after beating an enraged Flash. Taunting his nemesis by insisting on creating his own "family" of sinister speedsters, Reverse-Flash returns to his villainous roots. Not that their allegiance was meant to be long-lived, it is a shocking end to the tragic character of Godspeed, the former-villainous speedster who wanted nothing more than answers for his brother's murder. Having admitted to the murder, it will be interesting to see how The Flash brings justice to his arch-enemy, although he will probably have his hands full in the immediate future.