is one piece episode 399 filler?

A Marine rescue team enters the Human Auctioning House through the back door with the objective to secure the safety of the Celestial Dragons. Law throws the head that he previously severed back to the marines, shocking them as the head can still talk and feel its body.

Law uses his powers to cut up numerous soldiers. Luffy goes into Gear 3.

Kid uses his power to attract the Marines' weapons to him. The force is so strong that even weapons inside the house fly to Kid, who uses it to build a massive metallic arm.

The captains attack the soldiers as their crews walk out.