I think that younger sibling might be Fredrick..
omg, why'd u think that, care to share some thoughts?
In initial stage the tension between them were strange.. Also why Frederick?? It can be anyone else right?? Also his identity never revealed.. I think there might be reason behind being spy.. I also think that Victor is behind all these.. Like he is the one to hire him.. Also Frederick resembles Eiser and their personality also matches... Also he looks younger... Gosh I can't sort my thoughts I have my insights or am I reading into this too much... I don't know ahhhhh...
omg how come this never crossed my mind ! maybe their mother had an affair with someone and declared him dead so she could protect him ..
Yeah coz her husband is toxic psycho.. I too Think that's why she hid him to protect him.. That makes lots of sense..
i wonder if their younger sibling is truly dead or alive ... because the way i see it the plot is kinda predictable at this point.. so it'd be interesting to add another character , although there's that thing with frederick and i'm getting tired of the grayans ( except for eiser <3)