The three Kampfers transformed into Super Kampfers
The "Super" Kampfer condition is where the Kampfer body takes pushed into far beyond normal fighting capacity. And of course they produce an glowing aura around them.
Only Akane, Shizuku, and Mikoto were able to do this. This is also similar to Dragon Ball Z's Super Saiyan form in glowing aura but in different colors rather than the simple yellow.