Ying Yinfeng's Links
In her Module, Yinfeng is the second-in-command. Yinfeng looks up to Ai and sees her as a role model. She has a strong loyalty towards Ai, as both her leader and her friend. During moments of confusion or weakness, she will always look to Ai for guidance and support. Yinfeng is Ai's biggest advocate. She admires Ai's beauty, strength, intelligence, and leadership. She will be by Ai's side where she goes, if she can. Although Ai is very capable to take care of herself, Yinfeng's actions are almost that of a "body guard" to Ai. It makes Yinfeng happiest when she gets attention from Ai, although she does not show it outwardly. It isn't because she wants to hide her reverence to Ai, it's just because she is the kind of reserved person who doesn't naturally display much emotion. Yinfeng will protect Ai with her life and makes a show of doing so(Although they are immortal, they can still feel pain and be put out of business into a coma for a length of time when comes great bodily harm). Although Yinfeng has a submissive attitude towards Ai, it makes her very proud to know that Ai does not see her as an inferior and considers them equals and close friends. Yinfeng confides everything to Ai and knows Ai returns some of the favor.
Ai is the leader of her Module (three minor gods who work together). She feels much appreciation for Yinfengs constant way of following her every order and listening to her every word. She considers Yinfeng the one she trusts most. Ai is not one to show affection, but she makes more exceptions in rare moments for Yinfeng than for anyone else. However, she still treats Yinfeng with a professional attitude most of the time. Ai feels that personal relationships are a useless human want, but she understands the importance of them only from a pragmatist's point of view. She has grown used to Yinfeng's constant presence. Ai will protect Yinfeng at all costs, but she knows that Yinfeng can take care of herself, so does not step in to Yinfeng's battles unless she knows that shes in dire trouble. (It always surprises Yinfeng when she finds Ai standing in front of her during a losing battle, since Yinfeng feels that she should be the one to protect Ai and not the other way around.) Ai has told her many times that she has no such duty to do so.
Yinfeng does not hide the fact that she dislikes Lixue strongly, and this may in fact be the only true dislike out of any of the negative feelings shared between the three sisters. Her animosity towards Lixue is 100% due to Lixue's objections against Ai. In fact, Yinfeng does not care at all for any of the insulting jabs that Lixue throws at herself, if it is not towards Ai. The only behavior that can cause personal frustration in Yinfeng is when Lixue treats her as "weaker" than the other two, and refuses to duel her. When Lixue verbally assaults Ai, Yinfeng attempts to counter her and defend Ai before Ai gets the chance to talk. (Ai has told her she doesn't need to do this, but she doesn't stop trying.) In fact, Yinfeng probably feels more anger at Lixue's behavior towards Ai than Ai feels herself. She doesn't understand why Ai doesn't harbor the same hatred for Lixue. Lixue, however, ignores Yinfengs interceptions in favor of continuing jabbing at Ai. At best, Yinfeng tolerates Lixue and treats her as a respectable colleague. During the rare moments Lixue is acting kind to Ai, Yinfeng secretly enjoys it because she knows it makes Ai happy.
Lixue and Yinfeng are the least closest out of the three sisters. This is mainly since Yinfeng is such a close follower of Ai, that some of Lixue's animosity towards Ai leaks over to Yinfeng by extension. In fact, most communication she directs towards Yinfeng is to insult or mock her about her puppy-like obedience to Ai, as if she is "her human" - here she is making a reference to their occupation as Keepers of the Living and guardian of a human life. (She doesn't know that these insults doesn't bother Yinfeng at all.) Lixue doesn't have much respect for Yinfeng, and doesn't pay her much mind, thinking herself superior. She uses Yinfeng as her verbal "punching bag" when she's frustrated she can't get to Ai. She does not like physically fighting Yinfeng and refuses to do so, insisting that it "will be boring" and shes "not worth her time". (Actually, Lixue feels that fightng Yinfeng will be like "punching a girl," without better analogy.) However, when it comes down to it, and Lixue has to secretly admit to herself that she cares for her two sisters, her relationship with Yinfeng is that of a reluctant older sister who would protect her younger sister, but otherwise bully her. In fact, if Lixue ever had to save or help Yinfeng during battle, she would probably tell her along the way that she's "useless without Ai".