The Ispazars are main antagonists in the story, being confronted by the anti-hero sorcerer Maal Dweb. They apparently plot to overthrow him and rue his dominion, however, they are no match for his magic. Dweb defeats them by reverting them into the form of some of their early ancestors. (2)
"(...) there came a vibrant drumming as of great dragonwings. He peered from his hiding-place and saw in the double dawn the descent of the Ispazars, from whose webbed vans a darkness fell on the valley. Nearer they drew, and he saw their cold and scarlet eyes beneath scaly brows, their long, undulant bodies, their lizard limbs, and prehensile claws; and he heard the deep, articulate hissing of their voices. Then the petals closed about him blindly, shuddering and constrictive, as the flower-women recoiled from the swooping monsters. All was confusion, terror, tumult; but he knew, from his observation of the previous rape, that two of the Ispazars had encircled the flower's stem with their python-like tails, and were pulling it from the ground as a human sorcerer might pull a mandrake plant.
"They came toward him among the crowded vessels, walking erect in the fashion of men on their short lizard legs, their ribbed and sabled wings retracted behind them, and their eyes glaring redly in the gloom. Two of them were armed with long, sinuous-bladed knives; and others were equipped with enormous adamantine pestles, to be employed, no doubt, in bruising the flesh of the floral vampire."
"When they saw the enchanter; they were both startled and angered. Their necks and torsos began to swell like the hoods of cobras, and a great hissing rose among them, like the noise of jetted steam. Their aspect would have struck terror to the heart of any common man; but Maal Dweb confronted them calmly, repeating aloud, in low, even tones, a word of sovereign protective power."
"Then, presently, the cloud of vapor began to lift, and he saw the other Ispazars, who were now little larger than fen-snakes. Their wings had withered into useless frills, and they crept and hissed on the floor, amid the alembics and crucibles and athanors of their lost science."
Clark Ashton Smith, The Flower-Women
Just imagine a story in which Vizaphmal and Maal Dweb meet. That would be spectacular.
I don't think these two were in the same universe. VIzaphmal mentions general lack of humanoid aliens out there and Maal Dweb cycle clearly features such.