Ziying of Qin sibling Chengjiao
Being Qin Shi Huang's brother
Li Kaiyuan in his study stated that Qin Shi Huang only had three brothers of any kinds: one paternal half-brother (Chengjiao) and two maternal half-brothers (sons of Lao Ai), therefore Ziying, if indeed being another brother of his, would have had more mentions in Chengjiao's supposedly betrayal.
brother or sister kin