Six Paths Ten-Tails Coffin Seal

The sealing technique used by Obito and Madara Uchiha to seal the Ten-Tails into themselves, becoming the beast's jinchūriki. After performing the necessary hand seals while in close proximity to the Ten-Tails' body, the beast is quickly absorbed into the user's own body. Once the sealed is completed, the user enters the Six Paths Sage Technique. When Obito used this technique, his hair turned white.

It is apparently difficult to control the tailed beasts and this can cause the user to have a psychological collapse. The user needs to either have a suitably strong force of will, either inherently or by finding one, in order to gain control. If they do that, they'll obtain the power of a "god that shapes the land."

In the anime, when Obito sealed the Ten-Tails, a circular shell encased his body which shattered once the transformation was complete.