Not a lot to explain on this one. If you understood what's been going on the past few chapters then you understand what's going on in this one.
One thing of note: if you're not familiar with the terminology, a "terminal disciple" is the last disciple a master takes on, usually very late in their life. I don't know much more than that, but I assume that this last disciple is generally treated very well and is constantly by their master's side so they learn all they can before the master dies. The joke of him being called "terminal disciple" is that Xia wasn't close enough to death to actually warrant one, yet Hua was always (physically) close to him anyways.