I, uh, completely forgot that there was a plot involved.

 Maybe not so much Margaret, but I can see Henry joining with the improved suit and perhaps a bio weapon or two. As an engineer, I can imagine him having developed a couple fleshy tools to work with. I would put him under a utility where he’d have unorthodox means of getting. The problem with standard tools is that they’re rigid, so imagine a tool set with flexibility, and maintains the power to work like the rider ones do. Thin tendrils to pick locks and reach around small crevices. A hardened carapace for armor. Depending on how we want to treat the growth rate, we could have him tools he needs. If we want to get get crazier, he can grow a carapace and act more like a tank. 

Margaret might join or be sought for dealing with the monsters they come across should they run into any. She could at least help them know what to avoid and what to look for. She’s the kind of person who would go herself if they need that kid of help.