Yang Jing still had a Transformation Pill, but he chose not to have Chi Yu take it right away.
When Yinjiao underwent his Transformation, the resulting vision covered the entire Huangyuan Marketplace. Chi Yu's Talent was only slightly less than Yinjiao's, so it was highly likely that a vision would appear for her as well.
However, because of the Celestial Demon Bloodline within her, her vision likely wouldn't be a simple rainstorm like Yinjiao's. If a vision of rising miasmic clouds and a sky-borne rain of blood were to appear, the situation would become dire.
The Six Great Sects would undoubtedly see it as a provocation from the Demon Sect and would tear Huangyuan Marketplace apart to find the source of the vision.
