On the face of the [Demonic Statue of the Outer Path] grew no fewer than nine eyes, eight closed and one open.
In addition, densely packed column-like protrusions grew from the back of the [Demonic Statue of the Outer Path]. At first glance, they looked like tree roots, and a careful count revealed as many as ten.
Uchiha Minamoto noticed that one protrusion on the back of the [Demonic Statue of the Outer Path] was far longer than the surrounding "roots," resembling a long "tail."
"Is it because the Seven-Tails was sealed inside? Is that why it grew a 'tail'?"
How could Uchiha Minamoto not know that the [Demonic Statue of the Outer Path] had another name?
The Ten-Tails!
Although, strictly speaking.
The Demonic Statue of the Outer Path was not the same as the Ten-Tails.
But the Ten-Tails was the Demonic Statue of the Outer Path's "peak state."
The method for turning the Demonic Statue of the Outer Path back into the Ten-Tails was not difficult.
Like "putting an elephant into a refrigerator," it took three steps.
Step one: have the [Demonic Statue of the Outer Path] absorb the chakra of the Nine Tailed Beasts to replenish its own chakra.
Step two: have the [Demonic Statue of the Outer Path], its chakra restored, return to its plant form-the God Tree.
Step three: have the resurrected Kaguya Otsutsuki absorb the God Tree again, bringing forth the Ten-Tails.
Yes.
The Demonic Statue of the Outer Path was not the Ten-Tails.
The real "fusion formula" was-
Kaguya Otsutsuki + God Tree = Ten-Tails.
To be honest.
Uchiha Minamoto had little interest in the Ten-Tails.
But Kaguya Otsutsuki was on his mind somewhat.
In the ninja world.
Kaguya Otsutsuki had probably spent the longest time sealed away.
Even One-Tail Shukaku could not compare