The Convergence (A Ben 10 X DC Crossover)

A Ben 10 Justice League/Young Justice Crossover. Ben, Gwen, and Kevin get teleported to the DC Universe, where eventually the two universes merge in to one.

From Yesterday (Young Justice/ X-Men Evolution Fiction)

Dick Grayson receives a blast from his past when an old childhood friend from his days of traveling in Europe with Haley's Circus shows up out of the blue. Dick hasn't heard from or thought about Pietro Maximoff in years, and though he's psyched to see him again, he knows something's up. Pietro's running scared and...