Limbo: Border Jail

Using the power of the Rinnegan, the user projects an undetectable shadow of themselves into the invisible world known as. The shadow within Rinbo is generally impossible to detect or visually perceivable without the Rinnegan. However, Naruto Uzumaki gained the ability to sense its presence after receiving the chakra of all nine tailed beasts and half of the Sage of the Six Paths' power. Although it is invulnerable to most physical attacks, techniques which make use of the Sage of Six Paths' chakra can cause harm to the shadow.

The downside to this technique is that the user's shadow, after a set period of time, automatically returns to their body and it is left temporarily unusable. Any damage which the shadow had sustained is projected onto the user upon its return to them. Madara's shadow was strong enough to repel all nine tailed beasts in a single instance.

Trivia

 * Both the first word's furigana and the second word  refer to the Limbo, with リンボ being the Japanese way of writing Limbo and 辺獄 being an actual translation of the word's meaning.