Orochimaru reveals the true purpose of his research: Immortality . He peels away his face to show the stolen body of a girl, explaining his Living Corpse Reincarnation technique. He openly admits his goal is to take Sasuke’s body next.
Watch the intense moment Hiruzen Sarutobi prepares his final stand against Orochimaru's forbidden techniques: Naruto Episode 72
Regretting his past failure to stop Orochimaru, Hiruzen prepares the Dead Demon Consuming Seal , a forbidden technique developed by the Fourth Hokage that requires the user’s life as a sacrifice. Orochimaru reveals the true purpose of his research:
This episode is a pivotal moment in the Konoha Crush Arc , focusing on the high-stakes battle between the Third Hokage and Orochimaru. Naruto Episode 72