@BoneyM
A while back, you mentioned how the Colleges don't think that Skaven has actual sorcerers/mages, and that even bringing the corpse of the Eshin Sorcerer-Assassin wouldn't mean anything because a corpse doesn't prove he could wield magic.
But surely Mathilde could just
write a paper on her observations of the Skaven sorcerer? Especially since her standing with the Colleges is pretty damn high, her standing with the Emperor/Empress is pretty high, and her standing with Algard and Dragomas is
very high. She's a freaking Court Wizard to a
Karak, which should speak volumes about how trustworthy she is.
And it's pretty hard to doubt her or dismiss her observations as "potentially mistaken in what she saw" when she can say "I was literally mere feat from him when I witnessed him manipulate Ulgu and Dhar into a spell and kill someone else mere feet away from me with it, and no warpstone or device was used, and I'm exceptionally good at seeing the Winds of Magic, both ambiently and in people". At that point, you either accept her testimony or call her a liar.
Besides, the only evidence you can really
get that a race can cast magic is witness testimony, if the corpses of spellcasters are insufficient proof. And as the Grey College knows all too well, living witnesses of expert assassins using a lore of magic that is specialized for stealth and assassination are a rare thing indeed if said assassins want to keep it hidden.
And as for the paper--is a mage using a normal Wind--Ulgu, in this case--to manipulate Dhar rather than manipulating Dhar directly a novel idea to the Colleges? Or is that exactly what necromancy is, just with Shyish? Or does necromancy not have the same kind of purely indirect manipulate of dhar via Shyish as the Eshin Sorcerer's spell had (except with Ulgu)?