Truth Water

The Truth Water is a murky, dark, red liquid within a white vase from an unknown origin. Similar to Kumogakure's Falls of Truth, it allows a ninja to face their true self. After consumption, the user goes into a comatose state where they meet face to face with their inner self within their mind. This Dark Counterpart (闇カウンターパート, Yami Kauntāpāto), will be an corrupt and twisted exaggeration of what they themselves tried to keep deep down inside or qualities they try to ignore. If one does not except their counterpart as a part of them, they will awaken to find their real body overcome with a dark shroud as the two "permanently" separate into 2 entities, earning the Dark Counterpart freedom to live their own separate life and the user the guilt of releasing them into the world and dissatisfaction of not obtaining true closure of facing their true selves.

Trivia

 * The water is actually believed to be from a different dimension.