It is the third part of the Shikamaru Hiden arc, which spans from episodes 489 to 493.
During their investigation, they encounter Minoichi, a former Konoha Anbu who went missing during the last war. Interrogating him reveals the unsettling depth of Gengo's manipulative ideology. NarutoShippuden_Ep_491_SUB_ITA.mp4
Gengo uses his persuasive voice—a form of auditory genjutsu—to manipulate the crowd and Shikamaru's team. When Shikamaru attempts to rescue Sai, his friend retaliates, fully under Gengo's control. It is the third part of the Shikamaru
That night, the team moves to assassinate Gengo during a public speech at Fushū Castle. However, the mission takes a dark turn when Gengo reveals a restrained Sai . they encounter Minoichi