Isaak turned his attention back to Alexander and said, "careful mate, yes i know who Bellatrix is, are you a muggleborn? Bellatrix was probably the most infamous Death Eater in Voldemort's army of dark wizards and witches. how can you not know that?"

he was genuinely surprised that somebody didn't know who Bellatrix Lestrange, he was almost certain that this boy must have muggle parents in order to not know about the Dark Lord's top lieutenant.