The completely obvious reason that Madara knew about the appearance of the Eighth...

[BlacLord™]

Gate:

Spoiler

Tobirama invented it.

After all, he's invented everything else, so why not? XD

 

[Six Paths]

No, Just No.

 

[theacknowledgedone]

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The answer was right in front of us.

 

[HashiramaDescendant]

I wouldn't be able to finish the manga if that happened. :|

 

[Mr Hiru]

Why not? Tobirama is the king of the kinjutsus.

 

[Dantee]

High kage level tier shinobi would have info on a vast number of techniques but it's possible he did. He invented everything else after all.

 

[Joon]

Shit. Madara just has that knowledge or.... You could be right. Tobimaru is that guy. Da Best.

 

[Snape Uchiha]

this is a great theory to how opening the eight inner gates were invented

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[ObitoGokuKakashi]

Nice one! : D

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