Ryll: Kinda late reply to this but meh.

I still see the first time as just Zero because for one thing Fujikos style includes weapons it's not like she can't fight without weapons rather her style is heavily aimed towards it. And seeing as Zero at the time did not have any weapons at hand it crosses out a lot of Fujikos style.

Mikiri as we know is based on Judo, Zero used a little of this for example when she protected her artery when Takezou grabbed her since that's something Mikiri knew how to do and not Hibiki. And while there's no real proof Hibiki never really uses throws or I don't remember her using any while Zero did throw Takezou. Next thing is if the Zero that came out the first time was really based on Hibiki then Kosukegawa wouldn't have worried about being caught in a hold. Also he pointed out that if Zero is all of Motokos repressed anger then she wouldn't use any holds if he stood up to her and just attack head on.

The conclusion for me is simply that Hibikis style which is just punches and kicks more or less is far better suited in that situation to use that Judo and weapons. That's why I say it was just Zero and not based on just one of the three.

As for Zeros look, since she didn't have a own hairstyle it also helps to make her look more like Hibiki since she just lets her hair down. And I guess they just kept it that way, as for her face it doesn't change that much, I've always thought of Hibiki as a middle part between Mikiri and Fujiko when looking at her face so it makes sense that Zero is somewhat in between as well.