To be honest, I think Black may not die as White and he are connected so as I understood it's probable if one dies they other might die too. But indeed I can't see an end with Black alive either. Maybe, even if both keep alive, won't stay together. And if Black dies, it's to protect his brother after all.
But yeah it was weird how the mother worded it, as if Black is going to die either way because something's wrong with him(?). I'm actually scared of the drama we may live thanks to P'Nuchy and P'Nook's cruelty LOL