Demonic Statue of the Outer Path

The is a personal summon of Nagato and Tobi.

Background
During the Third Shinobi World War, Hanzō betrayed Akatsuki, fearing they'd grow too strong, having allied himself with Danzō Shimura and his Root ANBU. The ambush resulted in Yahiko's death. Distraught, Nagato summoned the Demonic Statue, which proceeded to pierce his back with a number of black rods, emaciating him. Nagato used the statue to launch a powerful attack, which resulted in the death of all but Hanzō.

Appearance
The statue is a giant, humanoid entity. When first summoned it burst out from the ground, with only its upper torso and arms visible. Its back has a number of spike-like protrusions. When it is first summoned by Nagato, the Statue is blindfolded. During subsequent Akatsuki appearances, nine slots for its (normally closed) eyes are present in the blindfold. In these appearances its arms are also bound in shackles and it has a bit in its mouth. When it was fully seen after being summoned by Tobi, it is seemingly wearing some form of robe, and when seen in Tobi's hideout, its ankles also appeared to be bound in shackles. The long protrusion of chakra amplifying metal from when it connected to Nagato is also present coming from its midsection resembling an umbilical cord. When summoned into battle the statue is not bound by restraints.

Abilities
The Statue is able to emit dragon-like forms of energy from its mouth. When these dragons come into contact with ordinary humans, the humans' souls are ripped from their bodies, killing them. When these dragons surround a jinchūriki or a tailed beast, the tailed beast's chakra is gathered to the Statue's mouth and stored inside for future use. Nagato wanted to use these beasts to create a weapon that could destroy a country. Tobi however, wants to reassemble them into the Ten-Tails.

As evident from his enormous size, the Statue possesses great strength, enough to clash with the likes of Chōza and Chōji Akimichi in their colossal forms. It was also shown to be durable enough to take one of Chōji's Butterfly Bullet Bombing punches without even being pushed back, and stop Kitsuchi's Earth Release: Sandwich Technique, just by outstretching its arms. It's capable of creating shock waves that can devastate an entire battlefield, and from the protrusions on its back, launch energy blasts.

Kazekage Rescue Arc
Years later, Nagato made it the means behind Akatsuki's tailed beast extraction. When Sasori and Deidara arrive in an Akatsuki hideout with Gaara, Nagato summons it to extract the One-Tailed Shukaku, over a period of three days, sealing it into the statue. When the sealing begins, the bit falls from the Statue's mouth. As the sealing nears completion, one of the eyes corresponding to the beast that is being sealed opens. After the sealing finishes, the statue disappears.

Hidan and Kakuzu Arc
The statue is summoned to seal two tailed beasts, the Two-Tails and the Three-Tails, during which process Nagato explains Akatsuki's goals. As a result, Yugito Nii dies.

Itachi Pursuit Arc
After Kisame captures Rōshi, the Four-Tails jinchūriki, he and Itachi discuss the sealing of the tailed-beasts. Itachi says that they don't need to rush to capture the Nine-Tails, since that beast is supposed to be the last one sealed, or else the statue would break apart.

Tsuchigumo Kinjutsu Arc
After the Six Paths of Pain capture Utakata, the Six-Tails is extracted and sealed into the statue, resulting in his death.

Invasion of Pain Arc
After Sasuke Uchiha captured "Killer B", the Eight-Tails jinchūriki, Akatsuki tried to seal the beast in the statue, only to see that it's actually a fake.

Five Kage Summit Arc
After Nagato's death, Tobi indicates that Nagato was just a pawn that the Demonic Statue had been synchronised with. He states he would like Sasuke to be Nagato's replacement, but decided to wait until Sasuke was easier to manipulate.

Shinobi World War Arc
After Kabuto allies himself with Tobi, Tobi shows him the statue in their headquarters at Mountains' Graveyard, where it sits on a giant lotus flower. At the stem of the flower supporting it, there is a copy of Hashirama Senju. The flower connects to an underground cave, where Tobi shows Kabuto that he has used the chakra of the captured tailed beasts to create an army of White Zetsu.

During the Fourth Shinobi World War, Tobi summons it on the battlefield to steal a substitute for the Nine-Tails' chakra. Later it is seen in a forest.