From what I can tell I'll summarize the story as I see it: In the original timeline, lamia orphe and her brother grew up into their respective role as duchess and knight, this timeline is one where the 2nd prince is friendly with lamia. For some reason though, (probably due to her position as duchess), she dies, and a grief-stricken 2nd prince turns back time, determined to save her at any cost. This is possible as 2nd prince is a descendant of a dragon, and memory flashes of the previous timeline for some reason appears in 2nd/current timeline lamia's dreams. In this second timeline, lamia decides to become a knight and her brother the duke, as the brother's dominant hand had been crippled by the 2nd prince, and lamia wanting to get revenge for him. The 2nd prince probably did it i hope of saving her this timeline even if he turns into a villain probably, which leads us to the current situation now. This is what I get from the story so far