Lerchenlied was Vika's milk sister, their bond was a complicated mix of sibling, master-servant, and a crush on the part of Vika. After her death, Vika dedicated himself to defending the nation, as it was Lerchenlied's one final wish. Vika lamented that he did not get to kiss her even once.
Zafar is Vika's reliable older brother and his candidate of choice for the succession of the throne. As they were both children born from Mariana Idinarohk, they have built a trusting and caring relationship. Unlike his half siblings, Zafar respects Vika despite his twisted tendecies. Vika attributes all of his military achievements to Zafar in support of his candidacy.
Lerche is a Sirin based on the personality of Lerchenlied. Lerche is subservient to Vika and follows his commands dutifully. She is capable of defying him, however, such as when she refused to tell him the details of a conversation between herself and Shin. She eventually acquiesced to his question once it was posed as a request rather than an order. Outside of duty, they have a playful quarrelling relationship.
Vika cherishes Lerche, she is one of the things he would allow himself to be sentimental towards. Vika intentionally created Lerche to be Lerchenlied's only vessel. Once Lerche fell on the battlefield, he would allow her the release of death, unlike the other Sirins who would be brought back into service. He is hurt when Lerche proposed that he finalize his marriage with a princess candidate. He dislikes the idea of choosing another woman, especially when she is the one asking him to.