Underworld Transfer Jutsu

Underworld Transfer Jutsu opens a filler arc as an anime-original threat involving soul-transfer techniques pulls the cast into a standalone story. The episode sets up the diversion within the war's gravity — a forbidden jutsu, a guest cast, a self-contained conflict. Sealed inside its own walls, it gives the audience a standalone tale. Competent filler setup, it builds toward a self-contained resolution, every consequence held within the arc and irrelevant to the canon war raging elsewhere in the timeline.