as someone who speaks Spanish and is trying to improve his English, an important part of understanding another language is the tone of words, I read the Spanish version first and find the brother at first acting in a more "dearest" way but then acting more imposing like Bane (do you feel in charge)... so if someone is kind to tell me how do you feel about Kaguya's brother words...
Pd I know that Zaibatsu translation is better