Dr Bustle DM, Phil, B.EI L, Patricius Professor of Magic. Dr Bustle was a powerful wizard at Unseen University. He was an expert on ancient languages and had a very high opinion of himself.
He decided to try to capture a Hiver as part of his latest dissertation. Unfortunately he succeeded. The Hiver willingly accepted this power and then - as is its wont - took over Dr Bustle and used him to further its own ends. It ended badly, as these things tend to do.
His unfinished dissertation is on display at the Unseen University Library. Research Students are encouraged to read it and reflect upon the manner of his death, presumably to show them what careless research can lead to. The effects of the Hiver on Bustle's mind is evident as the last few pages as the writing becomes blurred and smudged, filled with grandiose statements filled with paranoia and multiple exclamation marks. The writings suggest that he was opposed by the Archchancellor of the time and that he 'did something' to him. The precise nature of what he did to the Archchancellor is not mentioned.
Centuries later, when the Hiver invaded the body of Tiffany Aching, the ghostly memory of Sensibility Bustle awoke now and again (along with an ancient desert queen who killed ten of her husbands with scorpion sandwiches, giant lizards and sabre-toothed tigers - all the most powerful members of society on the Disc at the time).
When the Hiver was defeated through kindness, and disappeared across the Desert, for some reason the memory of Dr Bustle remained with Tiffany, and occasionally stirs to prompt her with erudite information or the translation of obtuse old words.