is one piece episode 853 filler?

Luffy attempts to stop Mascarpone and Joscarpone from shooting flaming arrows into the Thousand Sunny through a mirror, but his attacks are intercepted by Katakuri, who warns him to not attack his siblings before assaulting him. The arrows land in the men's room and set it on fire, and Luffy desperately tries calling out to the Sunny crew through a mirror shard.

The crew is busy dealing with Amande's fleet, with Jinbe steering the ship to avoid cannonballs and Chopper and Brook intercepting some of the shots.