Responses
Unless they explained it in the webtoon and I just am totally spacing out on it, I think the “her” his hallucination is referring to is his mother. Besides context, she’s the only other prominent female in Yoseob’s life other than Yura and Jaeha’s mother, who is obviously still alive.
That imaginary little Yoesob said that "He found out you were the one who killed her." Like Yeosob killed who? "Her" does he mean Yura? Yura ain't dead yet so who's the 'her'