With all the ruckus at the floating island platforms, there was another fierce battle in the seas of Pandapolis which no one could see. Even with the aid of high level magic, the Royal Mages could not accurately detect anything to make a proper assessment of the situation.
The Fog that Steals was something similar to an Anti-Magic Field, which was created to overload the mages' senses. The more sensitive one was to magic, the harder it was for them to do anything within it. So, with no magic acuity special visual senses to guide them, the Demon Fleet Leviathan relied solely on their seafaring instincts and years of experiences to bring them to victory.