is one piece episode 866 filler?

Luffy manages to predict Katakuri's attack and counter it, which surprises Katakuri as he realizes that Luffy's Observation Haki is developing. However, Katakuri manages to lay more hits on Luffy after this, and as Luffy attempts to see whether Katakuri will attack with Mogura or his mochi donuts next, Katakuri notes that Luffy's precognition is not as developed as his own and attacks with both.

Luffy does his best to dodge the attacks, but his fatigue begins catching up with him and, despite occasional good moves, he continues to be overwhelmed.