Eldritch Gotham + Bat Family Cursed to be Metahuman Au where Bruce Waynes meta power is being imperceptible, silly alien invasion shenanigans!
Bruce just straight up won't show up on sensors or scans unless he *wants* to be found. He can meld with the shadows at will because he's just willing himself to not be noticed. It's not invisibility, it's more like he creates his own personal blindspot in the universe. He doesn't notice any of this at first because he's spent years training himself to be stealthy anyways, but it starts to freak out people like J'onn and Clark, who should be able to sense him anyways and just can't. This is also how, despite dozens of people knowing Batman is Bruce Wayne, his secret never really gets out.
A bunch of aliens from way far away come to invade earth, and they spend a few days orbiting to try and scope out the heros and protectors. The aliens conclude that no earthly hero can outmatch them, and they easily begin to take over earth. The JL get captured, every single member imprisoned in ways that exploit their weakness except for Batman, who's been missing since the aliens showed up. Already, the JL is working on a way to bust out, but not before Batman shows up kicking alien ass.
The aliens start freaking out cuz "wtf who are you why didn't you show up on any scans we literally spent days researching". Turns out as soon as Batman noticed the aliens he willed himself to just stop existing to the normal world, which created a massive blindspot for not only Batman but all history related to Batman. Like pages torn out of books, information on him was just unreadable and unobtainable.
Batman proceeds to jailbreak his buddies and the JL collectively send the alien invaders packing. Insert epic fight scene I don't feel like writing...
