The Supposed Sealed Ability

is episode 207 of the original Naruto anime.

Synopsis
Naruto and the members of Team 8 head into Yakumo's house to find her with Kurenai, threatening to erase her former sensei from existence. It is revealed that the malicious entity known as the Ido dwelled within Yakumo's subconscious, and was the reason why her abilities were sealed away.It is unknown whether Ido is within her subconcious-ness or is sealed within her subconcious. Yakumo ultimately overcomes the Ido and realizes that Kurenai cared about her. Kurenai then returns to an overjoyed Team 8.