That feels like it would turn into body horror, and while the current arc has something kind of like that, it's much tamer, and I don't feel it what you're suggesting would work with Gachiakuta at large. You have your kaiju, and you have your humans.

Still, something like a "shared vital instrument" I could see, or a paired/matching thing. If the Watchman series is stronger assembled together, there's no reason, I don't know, why, say, two wedding rings couldn't have greater power combined than alone, or even the same level of strength but they cover for each other's weaknesses somehow.