I want them to team up with each other's future selves who decide to troll their respective kid rivals.
Damian: So...you're telling me that every girl I've been moderately...attracted...to...turns out to be gay?
Superman II: Don't take it personally, Dami. Could've happened to anyone.
Jon: But-but I die doing something awesome, right? I didn't like slip on a Kryptonite banana peel or something dumb like that, did I?
Batman III: Johnny, it'll be all right. I'm going to fund your memorial myself. It's going to be very regal and dignified, but telling you anything more about your future demise could seriously jeopardize the timeline.
Jon: But I die in this timeline!
Batman III: And you'll be missed. I promise.