Four-Tails (Steven-Kun)

The Four-Tails (四尾, Yonbi) is a tailed beast previously sealed within Rōshi of Iwagakure. It was at one point captured by Kisame Hoshigaki and later extracted and sealed by Akatsuki. After the fall of Madara Uchiha and Akatsuki, it was acquired by Sunagakure and later sealed into Hotaka Takeda.

Background
According to Madara Uchiha, the Four-Tails first came into being in the waning days of the Sage of the Six Paths' life; to prevent the Ten-Tails' resurgence, the Sage split up its chakra and used his Creation of All Things (万物創造, Banbutsu Sōzō) ability to create nine separate, monstrous constructs of living chakra, which would become known as the tailed beasts. The Four-Tails eventually fell into the possession of Iwagakure and was sealed into Rōshi at a young age. Kisame Hoshigaki later encountered and defeated Rōshi and the beast was then captured and extracted by the Akatsuki organization.

The Four-Tails was eventually set free after the defeat of Madara Uchiha and Akatsuki during the Fourth Shinobi World War. Iwagakure failed to recapture the beast which then ran rampant throughout the lands for years to follow. The Four-Tails eventually found its way to the Land of Wind where it began to unleash powerful attacks on villages within the nation. The ninja from Sunagakure arrived to combat the monster and most were promptly defeated and engulfed by the lava techniques of the Four-Tails. The Sixth Kazekage then arrived and combated the monster before it could successfully destroy Sunagakure. The Sixth Kazekage single-handedly battled the Four-Tails and was almost killed when facing the monster. After a long fight, the Sixth Kazekage was then able to subdue the Four-Tails and contain it within Sunagakure.