"Can you see me now?" "You wanted to die... I wanted to live."

Even sense the whole "family" of spider demons lives in a cruel, abusive world, there's a ray of gentle moonlight for all of them... Y/N,the eldest "child" of the family [Rus] Не смотря на то, что вся «семья» паучьих демонов живёт в жестоком мире, полном насилия, есть лучик ласкового лунного света для каждого из них... Т/И , старший «ребёнок» семьи

This is a platonic relationship since Rui is a child. The reader is just someone who is meant to care for him. And over time the reader just accepts it as their life, maybe even harboring some nurturing feelings towards him? We'll see how it goes.