Spirit Artifact - talk about the tool spirit and beast that's inside.
Blood Essence Body stops before Houtien Realm, and he didn't have the second jade slip that contained the information.
Add a line or two when Wei thinks about Alchemy Comphrehension Tower in book 1
mention of his dantian space and size of it - a regret, probably add a Dantian Strenthning Fruit reference.
A cut on his right shoulder. Reference in a first few chapters.
Add a line for One Sword Strike, how mythical the skill is one had to comphrehend, and how his fellow brothers had stuck in middle completion for their life.