WARNING: The following contains spoilers for Flash Forward #2, by Scott Lobdell, Brett Booth and Norm Rapmund, on sale now.
Justice League and the Avengers are definitely the two big superhero teams out there, so logically, fans want to see them fight. We've had crossovers over the years, of course, with Marvel vs. DC pitting various heroes against one another. Fans love to see characters who can never interact with one another face off, especially when said characters have reality-bending superpowers.
However, in Flash Forward #2, we see the Flash take on the Avengers and X-Men -- and win -- all on his own. Sort of. While the Flash doesn't interact with the real Avengers or real X-Men, we do see the DC equivalent of these two teams go up against the Flash, who makes an absolute mockery of both groups.
Who Are DC's Avengers and X-Men Stand-Ins?
The Retaliators and Zen-Men are DC's parody of the Avengers and X-Men, respectively. Both are obvious pastiches of the core teams, meant to stand in for the heroes. The Retaliators are a team of superheroes led by a shield-wielding hero named American Crusader who shouts phrases like "Retaliators ready!" or "Retaliators rampage!" The direct comparison between this and Captain America's alliterative catchphrase "Avengers assemble!" are pretty well evident. But it doesn't end there.
Next to The Retaliators, there are the Zen-Men, another satirical team parodying a Marvel team: the X-Men. If there is any debate on if the Zen-Men are a parody of the X-Men, consider first that the leader is named "One-Eye" and fires optic blasts. There is also a telekinetic red-haired woman and easy stand-ins for Wolverine and Gambit, among many others. Just look at the crop of the above page, and you sort of get the idea.
In both cases, these are legally-acceptable parodies and satires of established superhero teams, much like how Watchmen was a satire of the old Charlton Comics characters. However, DC has planted a little fun "tribute" to the Marvel teams in their newest book... by having Wally West beat all of them in a fight.
Flash Vs.The "Avengers" and The "X-Men"
Flash Forward takes Wally West, following Heroes in Crisis, throughout the multiverse on an adventure to set things right again. Along the way, he encounters the Retaliators and Zen-Men, and manages to beat them all in *ahem* rapid-fire succession. It isn't the primary point of the issue, nor even a huge focus, but it does establish that the Speed Force can overpower the entire Marvel Universe -- at least, in this satire of them.
The Flash completely disassembles the two opposing teams. It isn't even a challenge for him. Of course, considering the Flash can travel at the speed of light and faster, it makes sense that he'd be able to tear through each of them. After all, most of these people's power levels don't compare to his.
Of course, an actual fight against the Avengers and X-Men probably wouldn't end so easily. After all, against Thor or Phoenix, he'd have a far harder time than, say, against Captain America. However, considering these satires are both lacking the real heavy-hitters from both of the primary teams, Flash fought these teams on easy mode.