Ye Bai had traversed the Jianghu for so many years (adding up his past and present lives), and had never seen such an absurd thing.
The Thousand-Change Silkworm could not only devour crystal cores to learn skills, but also replace higher tiered similar skills.
The Steel Skill could make the whole body as hard as steel, greatly enhancing its defense capability, while the Hardening Skill could make the whole body hard, enhancing one's defense capability.
The Steel Skill is considered an advanced version of the Hardening Skill.
If Ye Bai didn't have the Eye of Insight, he wouldn't be able to detect this subtle anomaly and naturally wouldn't notice the special traits of the Thousand-Change Silkworm.
If all skills could be replaced like this, then the Thousand-Change Silkworm would be incredibly formidable.
Ye Bai's heart was pounding, but the prerequisite was that the Thousand-Change Silkworm itself already possessed many skills.