Quote Originally Posted by Kraco View Post
If it was Oro plus fully powered First and Second versus lone Third, I think the loser would be very swiftly obvious, even if we don't really know much about the First and Second's level of power.
Exactly.

From the observing ANBU's point of view, it seemed very much like a "Hokage-level battle" to him - I have no reason to doubt him.

The outcome showed that the Third had no way of defeating them, and resorted to the Death Seal, which not only kills him, but binds his mentors' souls to hell forever.

It was most certainly a one-sided battle.

Besides, how much sense does it make that by sacrificing some loser you get to resurrect some uber mofo with full powers yet completely obedient? If such a miracle technique existed, everybody and their cousins would be using it and all the fights in the series would be between zombies.

So, no, it wasn't said anywhere but logic dictates it.
The two Hokages weren't completely obedient until Oro put those two tags into them.

It was also mentioned that this was a Forbidden Technique, something that was sealed from general knowledge, and probably read by Oro when he camped those archives in his younger days.

Techniques require understanding to perform. Just because everybody knows the Substitution Technique doesn't mean they can all perform this.

Or, maybe they could, since as I said, we know nothing about it other than that it's forbidden.

edit: The following doesn't prove a point, but just for kicks, Oro had to gather samples from the First and Second to perform this - Third mentioned something about raiding their graves.