My point was that Nagash invented necromancy. It didn't exist before him. It was an apparently unprecedented blasphemy when he did so. If it was trivial for any random untrained magic user to come up with, Nagash wouldn't be the inventor of necromancy, random unknowns would have been independently inventing necromancy every year or so for thousands of years before him, particularly in a civilization that was fixated on the dead and their eventual reanimation. He would just be the refiner of necromancy, which is a much smaller and lesser thing.
The knowledge inside the book could make what's currently an incredibly arduous and pretty dangerous process that most necromancers do badly much easier, by giving concise, clear instructions, even if they're ending up with basically the same result in terms of what the dhar construct inside any given undead would look like. It could well be a question of process of weaving the dhar that the book explains, not the fact that you need use Shisi end up with some dhar woven back on itself
I don't think we're that far apart in how we think of this issue at least, not exactly on the same wavelength, but not very far apart, though perhaps I did a bad job of explaining myself
Necromancy started with Nagash yes, its creation was not trivial
A petty necromancer with limited idea of what they're doing is working off of incomplete knowledge, how they obtained that knowledge who knows, it all originates from Nagash's books and gets less complete as it moves away from him, notes and minor tomes containing fragmented knowledge probably, or maybe they prayed to Tzeentch and got some random bits of knowledge shoved into their brain along with a third eye or something
That sounds like something Tzeentch would do
Anyway the point is that there are gaps, they have some idea of what they want to do, and how to do it mixed in with a bunch of occult ritual and misunderstanding, but they are working with the incomplete picture
They probably don't understand how to properly weave Dhar upon itself to bring structure to the chaos, so they have to try and force the unstable energy radiating hate and evil into shape the hard way, maybe they even haphazardly come up with a method vaguely reminiscent of the first secret
I have a hard time believing that they don't end up ultimately bridging the missing pieces of what to do by just grabbing Dhar and forcing into the relative shape needed
I also don't believe that using another Wind + Dhar or pure Dhar would produce Necromancy. I think Necromancy is specifically the themes of Shyish perverted/inverted by Dhar. Another Wind plus Dhar would produce a different perversion, based on the themes of that Wind.
This on the other hand, may be where we will have to disagree, though I will clarify that I never meant to suggest that grabbing onto Dhar with any wind could crate necromancy, any wind other than Shyish would probably get in the way
Dhar is by definition the Winds mixed together, using Shyish to grab Dhar is not adding anything to Dhar that wasn't already there, it doesn't somehow change the equation such that necromancy suddenly becomes possible
I personally believe that Dhar can be used to produce necromancy on it's own by simply shaping it properly to achieve that effect
Grabbing on with Shyish just happens to be extremely helpful because that gives you something to help better steer Dhar in the direction you want
Though for the purposes of this quest at least it may also make shaping Dhar harder in other ways, going by Boney's comments on the matter
And as for humans not being able to directly handle Dhar, that makes no sense