"Would you like to see a wood elf forest without anyone trying to kill you?"
If you think that none of the Jade and Amber LMs have ever managed to see Laurelorn from the inside then you are suffering from serious protagonist goggles.
That your definition covers five different possible avenues and points to four existing models as possible frameworks highlights my exact point about 'theurgy' meaning many different things to many different people.
That's by design. All of those things are "Theurgy". If one of those things are possible for Mathilde without her stopping to be a Grey Wizard then "Theurgy" is a viable idea. If studying the Nehekharan method in order to combine her current magic with any form of Divine magic from any non-Chaos deity is viable then that covers the research direction that has been most often proposed. Another option would be applying the fabled Ulgu Thongs to some deity's Divine magic, though the question of how to source said magic would have to be solved as well. That would most probably lead to very different results, but it still falls under the "Theurgy" umbrella. "Theurgy" really is just the idea of having one caster combining Divine and Arcane magic into one casting technique.
Do not trust in meta shenanigans to protect Mathilde from the extremely real consequences of using an extremely toxic substances, especially when I have explicitly cautioned the thread about those consequences on multiple occasions.
That's not what I was trying to say. It's just that even if you roll to see if Mathilde does fucked up shit over the course of the turn as she pursues her goals, I still think that you would let us vote for her actual goals and courses of action. Otherwise it would mean that any serious amount of Dhar contamination would automatically lead to a bad end in which this stops being a Quest and starts being a prose epilogue of varying length.
I might need to invent a new level of extreme classification for that sort of publication.
Personal letter to the Grey Patriarch, to be given to the next Grey Patriarch?
Speaking of classified material, how does it work when Mathilde discovers some sort of magical knowledge that the Grey College would really like to keep as a Guild secret, not because it is too teach widely, but because they'd too like to have stuff like what every other College has. When would Mathilde be asked to make her paper a classified one and who would have the final say in the matter?
I suspect that learning the Lore Nagash invented may require adopting large parts of his mindset, as it's intimately bound up in the spells.
Supposedly Mathilde can already cast Necromancy and, whatever the mindset needed, it hasn't been mentioned to be very hard to reach for her or require a permanent paradigm shift. To me that says that someone who specializes in some form of Chaos Sorcery should also be able to pick up Necromancy, at least in a limited fashion.
Problems there is that Mindhole is at short range and a way to store a spell to execute at a later point wasn't invented until Mathildes Matrix, and if it were something like that were applied to her anyway then windsight would have seen it.
Anyway, I don't know this is too relevant to the original point, I misunderstood mindhole, doesn't really matter if its done with a different spell, and we kinda know that spells exist that aren't on the list because of Algard rearranging the sky and his pocket dimensions and stuff.
The relevance to your original point is that the Grey College most likely has
some kind of access to a spell that manipulates general memories of learnable knowledge in some fashion, even if said spell happens to not be called Mindhole as you thought it was. So, barring that specific spell name, your original argument still stands. And just because the spell is need to know doesn't mean that someone with access to it isn't abusing it anyway.
I think it's important to keep in mind the distinction that the Matrix allows any spell of its wind to be trigger packet implanted, where as what ever was done to Mathilde was probably a spell entirely of its own that worked in a similar fashion but the packet was its self part of the original spell rather than a modular addition. I don't think Windsight works well when directed inwards although tbh I'm not sure on that one but the way windsight has been described for Mathilde I'm not sure if she can gaze upon her own soul or look inwards so she might never have noticed it because of that. There's also the difficulty in noticing Ulgu when its in your brain and wreathed in Ulgu any way.
But yea, it's probably a custom spell of some sort, might be built off a mindhole mastery and recodified though.
She could look at freshly minted Grey Journeymen with zero Arcane Marks.
1) Noone but thread and Mathilde has expressed this opinion. Eonir want their stones online and Belegar wants to know what the fuck is up. Any advances beyond that, in repairing, maintaining or even making new stones are not only very high bar to shoot for, but also one that all participants will have to hash out how to spread. There is every possibility Eonir might not want that either.
If for whatever crazy reason we end up with a Waystone Project that results in zero applicable knowledge for Humanity/The Empire then I am definitely voting to screw our oaths on our deathbed and writing a detailed paper on every single thing we learned, to be distributed to the Grey Patriarch, the Supreme Patriarch and maybe a couple of other Patriarchs/LMs upon our death.
