is demon slayer: kimetsu no yaiba episode 19 filler?

Members from the Hashira of the Demon Slayer Corps have arrived on Mount Natagumo. Giyu Tomioka, the Water Hashira, slays the father of the Spider Demons with a single stroke of his sword.

Inosuke, thrilled to see such a display of swordsmanship by someone in a completely different league from himself, challenges Giyu to a duel. Meanwhile, the Insect Hashira, Shinobu Kocho, appears in front of Zenitsu, who lies near death as the poison circulates throughout his body…