Warning: contains spoilers for Justice League Incarnate #5!
Mary Marvel is about to become DC’s newest Shazam, and a recent adventure suggests her powers will make her as fast as speedster ally the Flash, and way faster than Superman. In Justice League Incarnate #5, the Mary Marvel of Earth-5 encounters Avery Cho's Flash and is able to match her speed, just as Avery has matched Barry Allen and Wally West in the past. Justice League Incarnate #5 is written by Joshua Williamson and Dennis Culver, drawn by Andrei Bressan and Jesus Merino, colored by Hi-Fi and lettered by Tom Napolitano.
Since her first appearance in 1942’s Captain Marvel Adventures #18, Mary Marvel has been an integral member of the Shazam family, and in the coming months, will become its primary champion in The New Champion of Shazam. However, another version of Mary Marvel, closer in spirit and intent to the original, resides on Earth-5 in DC’s multiverse, and is her world’s member of the Justice League Incarnate. The team, comprised of some of the most powerful heroes from across the multiverse, have been trying to stop the Great Darkness, even teaming with Darkseid to stand against it. As the Justice League Incarnate and Darkseid’s legions fought the Empty Hand on Earth-7, the Great Darkness took possession of some Incarnate members, including Mary Marvel.
Avery Ho, both the newest Flash and the newest recruit to the Justice League Incarnate, engages Mary Marvel, who is possessed by the Great Darkness. While Avery is a true speedster - drawing on DC's Speed Force, and a match for Barry Allen himself - she nevertheless finds that she can't shake Mary Marvel no matters how fast she runs, calling to Doctor Multiverse that, "Mary Marvel keeps matching my speed. She has me trapped." Only upon embracing truly out of the box thinking - letting her speed run out of control - is she able to give Mary the slip. Eventually, working in tandem with Doctor Multiverse, the Flash is able to free Mary Marvel and the other possessed members of the Justice League Incarnate. However, the fact that Mary can keep up with a Flash is stunning news.
It should come as no surprise that Mary Marvel, who possesses the speed of Hermes, would be super-fast - just not this fast, especially for someone who does not tap into the Speed Force, such as the Flash. While Mary keeping pace could be ascribed to this Flash's relatively green status, Avery Ho exists in the top bracket of DC's speedsters, suggesting Mary may actually be able to match Speed Force abilities. Even more impressive is this in theory makes Mary Marvel faster than Superman. The Man of Steel can travel fast, but not as fast as the Flash - indeed, whenever the two race against each other, the Flash lets Superman win.
If the mainstream Mary Marvel is similar to her Earth-5 counterpart (and there's every reason to think this is the case, as it's true for the rest of the Incarnate team's relationships to their original heroes), this opens some intriguing possibilities for the future. As mentioned earlier, Mary Marvel will soon become the primary champion of Shazam, replacing Billy Batson. However, Billy generally opts to be more of a powerhouse who punches his way through his foes. Could Mary take a different approach, using speed instead of strength? Mary Marvel has been depicted as one of the smartest members of the Shazam family, but now she is also the fastest. Being able to keep pace with Flash means that when she soon takes up the mantle, she'll apparently be using her powers very differently than the Shazam fans know, illustrating how her mystic might gives her abilities even Superman can't match.