Shinigami's Shrine

This technique was developed by Sannoto Senju as a defense, to prevent invaders from entering Konohagakure. This is Sannoto's most feared technique, and for good reason. First by forming four handseals, Sannoto utilizes the Iron in the soil in which he grow massive trees in a blink of an eye.

After growing the forest, each tree which is alive, emits Iron("Gas Form") from it's roots filling the forest with Iron Gas, which hold the same characteristics, as the Iron from Sannoto's other technique Iron Release: Hollow Gas.

On top of that, the Forest itself is surrounded in a massive genjutsu, specifically the Bringer-of-Darkness-Technique and the Echoes in the Dark Technique, canceling out the unfortunate victims sense of sight and hearing. Not to mention the Tree's continue to become larger by the second, so even if the victim is able to avoid the gas, the genjustsu is capable of restraining them until the forest grows over them, resulting in their death.