Content: (please note that content portions of a review may contain spoilers)
The episode opens with a brief and unsuccessful attempt at humor; Inu Yasha swatting a bug with the Wind Scar makes little sense and just is not funny. However, the remainder of the episode begins to heat up the actual plot as it draws close to its conclusion.
Byakuya lures Sesshomaru away from an unconscious Kohaku with a fragment of Magatsuhi's previous body. This diversion gives Magatsuhi enough time to possess Kohaku. Miroku and Sango attempt to stop the body snatching but are both gravely wounded. Miroku is close to death, either by the poison near his chest or from the new tear in his Wind Tunnel.
Magatsuhi feels victory and a complete Shikon Jewel are near, but Sango appeals to Kohaku to wake up and regain control over his body. Something in Kohaku's soul, aided by left over Kikyo magic, realizes that there is one last chance for him to redeem his past sins and defeat Naraku. He leaps to his death using the remaining essence of Kikyo to help him drive out Magatsuhi.
The emotional moments here are familiar elements of the story, but they serve well enough here to start building up some heat behind the story. We are nearing the conclusion, and this is the sort of material needed. Eighteen episodes have passed and have provided little reason to anticipate the final showdown. This is a key turning point, one that finally begins building that anticipation.