Luffy, Jinbe, and Sanji manage to reach the second floor of the castle with Jinbe telling Luffy that the roof is above the fifth floor. Suddenly, Sanji asks the two of them if they can hear that sound from the third floor. He focuses and hears someone speaking in a seductive voice.
Black Maria is on Floor 3, and Sanji’s Observation Haki allows him to hear what she’s doing with the courtesans – she’s about to start a new song when she hears that the caos is finally coming to her floor. Which could mean Kalifa 2.0, or something else entirely.
Even though it’s played for laughs for the most part it’s pretty cool to see Sanji’s Observation Haki surpassing Luffy’s in his own way right there by being able to sense what was going on on the third floor when Luffy and Jinbe seemed totally unaware.
Next few chapters may have some Sanji love since the chapter ends with the narrator mentioning how “ELECTRICITY RUNS THROUGH HIS BODY!!!” In fact I really do think this whole war will really rehabilitate post-timeskip Sanji for a lot of fans since he’s already had some MVP moments like freeing Momonosuke.
At first, with the unofficial translation, many thought that the person in question was Emporio Ivankov. Why? The laugh was Nfufufu, it made the Ivankov gag of: Just kidding! and it made Sanji upsted, wich would make sense.
However, now with the official translation, we can say that it’s probably Black Maria. The laugh is different, it has hearts on the text, which Black Maria does have, and it’s making a japanese gag about being undressed by a lord, wich would make Sanji extremely shocked and mad as he is a pervert.
So, Black Maria is about to do the nasty with an unknown character, or she is setting a trap to Sanji, wich he would fall so easily into.