@Zero: Err.... tampering the registry in an IS is a bad idea.... IS can alter human body...
So...
After taking a blow, the IS check to ensure the safety of the pilot... and find abnormality (since the pilot is a male), it will try to correct the problem by turning the Male into Female....
Luckily, it is possible to change the now-female pilot back to her/his original gender (by adding additional line of reverting pilot back to 'original state' at the end)
However, in an event (such as Ichika's one-hit kill) which cause the IS to shut down suddenly(Akin to suddenly switching off the main power supply...of a computer without letting it perform a system shutdown)......
There will be two problems:
1) The Pilot restoration line is not performed
2) There is not enough power to revert pilot back (Due to all energy went into Absolute barrier)
In both cases: the male pilot is screwed and trapped inside a female body forever....
@Eratas: My current explanation is The Prototype core is made together with Male engineers who ran a few system check on their own (test run the suit without female pilots).
White Knight core is special because it is made solely by Tabane without any involvement by others.
Alternative explanation: Prototype IS core can reprogram itself to accept male pilot.... because she is exy of Excalibur(from soul eater.... that damn annoying weapon who can can be used any meister....so long as they can stand him
) and Cipher is the only saint (only when come to woman) who can tolerate her.....
==
Question:
Is it a good idea to let the reader can speculate on the special machine which the male OC pilot?
For them to come up with two possibility:
Mundane
1. The Machine is really just man-made and was hand over to the male oc. (the explanation given)
or some thing absurd:
2. The Male Oc might actually be an alien....
The number 2 appeared plausible in the story because of The male OC's ability to survive in otherwise dangerous and violent situation and came out alive (which most people would hand-wave as rule of funny...but in my story, it is made as a counter-argument against the male oc as a normal human)
Also as a running gag: Served as his berserk button when ever the absurd explanation came up:
Narrator: "He angst about the possibility that he might actually be Time Traveling psychic Alien Parasitic Machine Emperor God from another Dimension"
Oc: "I don't! Stop making stuff like that up!"
Edit:
Ichika play along.... sometimes....
Ichika: "That's Alien Machine Emperor Z for you!"
OC: "I am going to punch you if you say that again"