Fantastical Evolutions

[Sirrocco]

...on the other hand, this is a magic-based world. Throw in a connection to six as a magically significant number, and some secondary subtle magics that can only be done with six primary limbs (and that require only the physical actions, and possibly life, and that are simple enough both in trigger and in effect to be both activated and exploited by lower lifeforms) and *everyone* jumps on that bandwagon. Likewise, a bit of magic in the right places makes a whole lot of kinds of anatomy significantly more plausible.

[Necratoid]

*A scene plays out in which Kasumi is mauling Saffrom, The Nerima Wrecking Crew, The Musk Dynasty, a winged tenticled minotaur, the complete Amazon nations of China, and seven Majin Bus at the same time, winning in 22 seconds without property damage. with one hand. SS4 Goku is weeping in the foreground in jelousy... suddenly the scene is blotted out in thousands of red boxed, 'NO!'s*
*Necratoid tosses Physics back its rubber stamp*
Anyway, no. I will not except that with the outline I gave that that is a functional theory of merit. That the Nekokai have a split tail with two extra handslike parts on it. This means 8 major limbs and your De Ex Machina the magic of the number 6 is flushed. Sure we could alter the theory for a different number or a group of numbers, but no.
Considering its already mentioned that they can travel and live on Earth permenently and that only one male can be in an area, then you have them die off from lack of magic to substain them, meaning the batteries of mana are required. No, I don't except magic means your right on this, because you can't prove it isn't true because it wasn't flat out said so. It reaks of Kasumi Tendo being the clear best MADM in the series, because its not proven she isn't the God of MA.
Besides that is the 3rd world's antotomical history, which is why they can't figure themselves out either. I've already stated that the 3rd world is the source of magic in my explaination. Adding magic says, 'Do it, don't bother trying to explain it, once a method is vaguely defined' is mindless. Not to start a religious debate, but its exactly the same kind of theory that disproves a creater deity by declaring that a method, of using to rules of the reality to do what is a miracle in the holy text, is found... therefore the creater deity is nonexistant, as the thing is possible in the first place, without a miracle. The 'logic' being that a creater deity would just ignore the rules of the universe/world, it when through the effort of creating in the first place, in order to make what it did more of a miracle... Converted to a business, it means the founder of the company can't fire you using the paperwork chain, because the paper work chain was created by the founder.
I just don't understand why they can do it with a constant inflow of magic, and without magic they'd implode is a better idea then they have a biologically functional method of functioning and are only enhanced by magic is a better idea. Having their number system on based 26 (5 finger times four hands plus 6 tail digits) makes sense. Having 6 be a major magical number makes sense. Declaring even though you just made a logically coherent and funtional explination for how things work and how some of their biology functions lets declare a wizard did it and go from that vague basis, doesn't for reasons listed above.