I have to wonder if Tanya Degurechaff might appear, since the... mechanic of flight for mages in that series is fairly comparable to the description von Hammer gives of WWI Witch hardware, and Tanya is operating in a WWI environment.

I have to suspect that if she did appear it would be in an adversarial role much like a witch equivalent of von Reichenberg. Albeit one not likely to engage in such showboating.

She's got strong magic, no deficiency in courage or intelligence... and she's a horrible person. "A monster in the form of a little girl," is the term used at the end of the first episode.