Warning! Spoilers for The Flash #751 below
The Flash has a new villain in town, Paradox, along with a familiar foe in Godspeed. Paradox has come for revenge on Barry Allen and he might have got it, seemingly killing him in The Flash #751.
In The Flash #750, a new deadly villain called Paradox shows up on Earth, using Godspeed as his messenger. Previously teased in The Flash #87 as a person affected by the Flash's fight with Turtle in Central City, Paradox is ready to get some revenge on Barry for (seemingly) turning him into a monster. Paradox wants The Flash to pay for his crimes and is willing to take him out to get justice.
In The Flash #751 by Joshua Williamson, Christian Duce, Luis Guerrero, and Howard Porter, Barry comes face-to-face with Paradox, after chasing Godspeed around Central City. The monstrous villain tells Barry he's responsible for bringing horror to reality, and tells him he's ruined "billions" of lives with his selfishness during Flashpoint. Paradox wants to get rid of The Flash to save the multiverse. Paradox is also harnessing crisis energy, which is released when time changes - killing the Flash will make him a literal god. After revealing his plan, Godspeed tells Barry he's on his side and was working with Paradox to get inside information. The two fight Paradox, but it doesn't go well for the speedsters.
Paradox sees the betrayal coming and quickly dispatches of Godpseed by throwing him hard against the ground. Paradox further reveals he was there in Central City during The Flash's fight with Turtle - and that while his refusal to never give up inspired the city, the event "took everything from" Paradox, including his family. Iris relays that the future Commander Cold's files indicating Paradox was beaten in the 25th Century by a speedster, the Reverse-Flash (who he'll have to work with in future issues). As Barry gets the information, Paradox throws him around, telling him he should have stayed dead before unleashing a blast of energy that seemingly evaporates the speedster. Paradox grabs Godspeed and leaves the scene.
Barry wakes up in a field of grass but has no connection to Iris or the world as he knows it. He hears a voice when he turns around, he sees his dead mom, who looks very much alive. The likelihood The Flash has been absorbed into some sort of Speed Force realm or afterlife-like reality seems likely, given Paradox's full powers are still somewhat unknown at this point. Did the crisis energy send Barry into a new plane of existence? Is he in the Speedforce? Is he dead? The issue ends on one heck of a cliffhanger. The Flash #751 proved Paradox is more than just a villain with criminal intentions, he's there to rid Barry from existence - and he might have just succeeded.