The whirlpool indeed repelled the Octopus King, as its speed decreased progressively as it entered it. Yet, the creature continued to struggle forward. Albeit at a snail's pace, it was indeed inching closer and closer to the whirlpool's center.
Mu You realized that he had underestimated this cephalopod. It was trying to forcefully break the expulsion rule of Dawn City by pure brute force.
Of course, the whirlpool's repulsive force was no pushover. The further the Octopus King swam, the slower it became. By the time it reached the middle layer of the whirlpool, it was almost stagnant.
What terrified the crowd more, however, was what came next: finding itself unable to advance further, the Octopus King suddenly shook its eight legs and extended a long, thin tip from each one.
The slender octopus limbs stretched out from beneath the sea surface, entangling several nearby boats, including Mu You's small boat.