Kagerōmaru

was the fifth incarnation of Naraku created for kill Inuyasha, and is also the demon who lives inside his younger brother Jūrōmaru.

History
Upon Jūrōmaru's introduction, it is patently obvious that Kagerōmaru is the one, and only one who seems to have control of Jūrōmaru, due to Jūrōmaru immediately slaying his "master" (Naraku's demon puppet) once his shackles were removed. Initially, Kagerōmaru and Jūrōmaru are able to overwhelm Inuyasha and Kōga in battle due to their unpredictable movements and abilities, with Kagerōmaru diving underground and then back above ground with astounding speed. Later on however, Kagerōmaru is considerably slowed down by a miasma that Sango injects into the ground. Kagerōmaru is then kicked by Kōga, and finished off by Inuyasha with a Tessaiga's slash.

Powers & Abilities

 * Keen Intellect: Kagerōmaru appears to have a crafty, sinister intelligence, which he uses to his advantage over the rather hot-headed Kōga and Inuyasha. This makes him much more dangerous than his host/brother, Jūrōmaru, who is more of a puppet with limited consciousness.
 * Digging: Kagerōmaru has the ability to dig deep in the soil, and pop up out of the ground at any given time.
 * Enhanced Speed: Kagerōmaru, as well as his brother Jūrōmaru, have superior speed. However, Kagerōmaru's speed is arguably at least twice as fast as Jūrōmaru's.

Trivia

 * Unlike Naraku's other incarnations, Kagerōmaru doesn't have a spider burn mark on his back.