Who is the monster?

Aru's shout brought Robin's attention to him again, and he spoke with a laugh, " Do you think shutting a few mouths would make any difference? Even if all of your tongues were cut out, do you think that would prevent me from knowing the truth? The truth about the destruction of most of your armies has become a reality in my eyes and the case is closed. Who can stop the demon army now? By using the Heavenly Major Space Law I can determine the locations of the rest of your army concentration points and major cities over this half of the planet within one hour and send to each of them a demon army to level them with the ground, while you will remain here playing with me and the Demon Emperors. Do you think that whether you talk to me or not will make any difference? You do not have secrets in front of me. In my eyes, you are as naked as the day your mothers gave birth to you!"