Shazam/capitain marvel mecha au in wich the equivalent of the adult-magical versions of the kids are mechas that have some level of personality and preferences over who gets to pilot them.
Tawny can be some sort of ai that helps them and can shift between a physical (robotic) body and just being in the computer.
The wizard is the "creator" kinda, and he only calls the kids because of "i'd thought we had more time, etc, etc. You get the idea.
I can decide if the kids would have to get "in" the mechas and make the other heroes pass for the horror of "that super deadly machine was controlled by a child" as a revelation or to have them to sorta of "posses" the mechas with their bodys being somewhere else and have a "that machine that feel human was nothing but a machine on the inside" instead.
