So, an interesting thought is the dichotomy between Li Suyin's hypothetical domain and Kang Zihao's predicted domain.
I believe that Li Suyin's domain will revolve around "Using the unpleasant for useful means" or something along those lines. Her most recent crafting exploits revolve around that. The bone soldiers, the impurity devourer, and her desire to use the materials found in these caverns for her projects. Additionally, that theme also allows her to rationalize what she considers unpleasant about herself (ie. her vindictiveness) and accept that part about herself.
Kang Zihao, on the other hand, seems to deal primarily with the appearance of virtue. Of appearing like the knight in shining armor, of appearing unblemished and unstained in the face of danger. He seems to care more about his actions appearing pleasing than the actual usefulness of the actions. This can be seen when he ditches allies who have failed him. Presumably, so that he can distance himself from failure. Even when not ditching them might be more useful down the road.
I think that these two characters are going to be diametrically opposed during their stay at the inner sect. Not only where they on opposite sides of the Outer Sect Conflict, but the core philosophies are also on opposite sides of the spectrum. One deals with turning ugly and nightmarish things into something useful, while the other cares only about appearing virtuous possibly to the detriment of actual usefulness. Additionally, one is a fighter and the other is a crafter.
There just seems to be so much potential for conflict between the two ideologies. And while the conservative side of me wants to say that there will be no conflict between them simply because they operate on different levels of society at the moment, the more adventurous side of me thinks that it is possible that a true nemesis relationship could develop between the two of them.
Admittedly, Li Suyin could develop a domain that revolves around an entirely different idea. I find that unlikely, however, given the amount of work that she has put into developing this line of products. Additionally, Li Suyin has felt first hand how thin the veneer of the virtuous is given her troubles in the outer sect. Furthermore, the idea of looking at the world and seeing the ugly, nasty, and nightmarish reality underlying a lot of the world and dedicating to turning those things into something useful just feels like a powerful direction for Li Suyin to go.