I can’t recommend highly enough this collection. Just look at those covers! Note the inclusion of CAS himself, from young to mature from book 1 to 4. Volume 3 has three Averoigne stories: The Holiness of Azédarac, The Makers of Gargoyles and the Colossus of Ylourgne. Those are less evocative than the previous ones in my opinion but in some ways they offer more background material for the Averoigne setting and, moreover, excellent gaming material.

The Holiness of Azédarac

• […] I wisely thought to review my library; and I have found that the Book of Eibon, which contains the oldest incantations, and the secret, man-forgotten lore of Iog-Sotôt and Sodagui, is now missing.
• In a chill flash of horror, his memory told him that the thin, pointed features behind the square beard were dubiously similar to those of Jehan Mauvaissoir, whom he had often seen in the household of Azédarac, and who, as he had reason to believe, was implicated in the Bishop’s sorceries.
• « I am Moriamis, the enchantress, and the Druids fear my magic, which is more sovereign and more excellent than theirs, though I use it only for the welfare of men and not for their bale and bane. »
• He [Azédarac] was the wisest and the mightiest of sorcerers, and the most secret withal ; for no one knew the time and the manner of his coming into Averoigne, or the fashion in which he had procured the immemorial Book of Eibon, whose runic writings were beyond the lore of all other wizards. He was a master of all enchantments and all demons, and likewise a compounder of mighty potions. Among these were certain philters, blended with potent spells and possessed of unique virtue, that would send the drinker backward or onward in time.

The Makers of Gargoyles

• At that time, in the year of our Lord, 1138, Vyônes was the principal town of the province of Averoigne. On two sides the great, shadow-haunted forest, a place of equivocal legends, of loupsgarous and phantoms, approached to the very walls and flung its umbrage upon them at early forenoon and evening. On the other sides there lay cultivated fields, and gentle streams that meandered among willows or poplars, and roads that ran through an open plain to the high châteaux of nobles lords and to regions beyond Averoigne.
• Of course, as in all medieval towns, there had been occasional instances of alleged sorcery or demoniacal possession; and, once or twice, the perilous temptations of succubi had made their inroads on the pious virtue of Vyônes. But this was nothing more than might be expected, in a world where the Devil and his works were always more or less rampant. No one could possibly have anticipated the reign of infernal horrors that was to make hideous the latter months of autumns, following the cathedral’s erection.
• Armed with holy water and aspergillus, and accompanied by many of the towns-people carrying torches and staves and halberds, the priest was led by Maspier to the place of the horro; and there they had found the body of Mazzal, with fearfully mangled face, and the throat and bosom lined with bloody lacerations. The demoniac assailant had flown; and it was not seen or encountered again that night; but those who had beheld its work returned aghast to their homes, feeling that a creature of nethermost hell had come to visit the city, and perchance to abide therein.

The Colossus of Ylourgne

• The thrice-infamous Nathaire, alchemist, astrologer and necromancer, with his ten devil-given pupils, had departed very suddenly and under circumstances of strict secrecy from the town of Vyônes. It was widely thought, among the people of that vicinage, that his departure had been prompted by a salutary fear of ecclessiastical thumbscrews and fagots. Other wizards, less notorious than he, had already gone to the stake during a year of unusual inquisitory zeal; and it was well-known that Nathaire had incurred the reprobation of the Church.
• Among the people of the city, there was one man who took no part in the somber gossip and lurid speculation. This man was Gaspard du Nord, himself a student of the proscribed sciences, who had been numbered for a year among the pupils of Nathaire but had chosen to withdraw quietly from the master’s household after learning the enormities that would attend his further initiation. He had, however, taken with him much rare and peculiar knowledge, together with a certain insight into the baleful powers and night-dark motives of the necromancer.
• Ylourgne, a great, craggy pile that had been built by a line of evil and marauding barons now extinct, was a place that even the goatherds preferred to shun. The wrathful specters of its bloody lords were said to move turbulently in its crumbling halls; and its châtelaines were the Undead. No one cared to dwell in the shadow of its cliff-founded walls; and the nearest abode of living men was a small Cistercian monastery, more than a mile away on the opposite slope of the valley.