is one piece episode 357 filler?

The Wild Zombies are surprised that the Negative Hollows are not working on Usopp. The sniper needed backup, but is left to go at it alone.

Perona fears for her downfall and summons more ghosts determined to rob Usopp of his will to fight. It seems to be effective this time, but the ghosts fail yet again.

Even with Usopp's negative personality, he becomes confident in his battle. As the Wild Zombies move in, they are shot with Salt Stars, purifying more of them.

The animals close their moves and chase the sniper around.