Questionable Questing

This is assuming that magi don't already have immuno supressants because lol alchemy, but eh.

Magecraft can only accomplish end effects mundane methods have also accomplished, as a general rule. Tissue rejection suppression seems like a thing of that sort.

That being said, there are lots of neurons that can be sacrificed without too much real loss. Like a bunch of sensory neurons on your scalp, say.

Not to mention the various different senses, pain and touch are actually different sense BTW. Entirely separate system and receptors.

Also, there are different diseases and animals that suppress the immune system, AIDS for example.

And I want to explicitly state I'm not being mean, or a dick before I say I have no idea where you got the idea that magecraft could only do what mundane methods have accomplished.

It runs counter to the fact that magecraft did everything science could before science was around.

Common Sense and scientific understanding is actually damaging magecraft.

It's simple - Magecraft can only do what mundane methods have accomplished, because anything mundane methods haven't accomplished is a True Magic.
That's fundamental to the definition of magecraft (the recreation of what was once a miracle), and True Magic (Miracles, things which no mundane means can accomplish)

That being said, the definitions can shift backwards. True Magic isn't just 'things that haven't been done through mundane means', it's 'things that cannot be reproduced by any other means, no matter the time and resources, in the current era'. What was possible has shifted over time. The end of the age of gods definitely changed the lines of demarcation, since all the phantasmal beings were gone.

The reason common sense and scientific understanding damage magecraft is not that they make the things it does more possible, but that magecraft is built on a very grand and widespread belief in the underlying system, whether it be western mysticism, eastern philosophy, or religion. Disbelief in the mystical and divine are the actual things harming magecraft.

Apparently during the age of the gods the rules of reality were so loose that magecraft and magic were near indistinguishable.

That being said I might be wrong about magecraft being unable to be the thing that narrows the category of what's 'Magic', though I'd imagine that'd be absurdly difficult. Either that, or just very unlikely, but...if 'Preventing Transplant Rejection' is meant to be possible by some means in the current era, I suppose magecraft could precede the mundane solution.

...and also natural phenomena are meant to be possible via magecraft, so I suppose I'm the one who isn't correct here.

I get that you're trying to prevent the Family from being hilariously broken, but that's basically what they are.

While Shirou is a terrible magus he is a good example that magecraft isn't dead, only stagnant.

An enterprising group or individual can actually get pretty far by gitting gud at the basics and then specialising in a field.

But magi have essentially given up on magecraft, it is only a tool to reach magic.

The Family has either given up or never even cared about Magic, and rather focused on improving magecraft at its core.

Fun fact btw, pump enough prana into literally any spell and it can become Hight Thaumaturgy, it's just a matter of whether or not it's worth it.

I think the more prana you have at your disposal the less important Mystery gets.

Magic and the Root are the result of treating magecraft as the means to some esoteric ambition. The family was gifted with magecraft by their benefactor, and treats magecraft both as a means to it's own end, and as a means to their own happiness.

My intention is mostly to paint nerve circuits as something that either by inheritance or self manufacture, you need a LOT of in order to even equal Shirou's magic output. Their academic study of modern neurology, as a family, came from a desire to trivialize the sacrifice of nerves. Later growing into the desire to not be sacrificing something from their own body at all, instead farming nerves to circuitify.

One of the more important problems the family faces, in my mind: they have a very limited range of spells outside of those they've made, since they don't exactly have access to the general academia of the Association. Runes would probably be a good field for them, because it's a system for the easy construction of spells.

Wait until they have a kid with reasonable natural circuits, ship 'em off to the clock tower for a while.

Just don't let them make any nerve circuits before they go, and play up the withdrawn starry eyed Asian from bumfuck nowhere.

Having absolutely zero circuits across the entire family is abnormal.

I mean, they're not from a magus bloodline at all, by common reckoning, and even a fallen magus bloodline like the Aozakis or the Matous can end up with most members having essentially no circuits. Those of them born with natural circuits would probably be born with...very few, very bad ones.

I suppose, though, the easiest contact for them in the Mage's Association would be heading to Fuyuki, a place important enough to have a second owner. Maybe an introduction to the Clock Tower by a Tohsaka, and generations of concentrating all of the natural circuits that emerged into one crest (not for passing down a bunch of knowledge, but to concentrate the prana capacity) would mean they could get someone in.