So who is he?

[Devauzamaki]

Madara seen naruto and said his name then said no this guy slightly different.
So did NARUTOS chakra sig change or gai knock a few screws out of madara?

 

[Memento Mori]

Madara seen naruto and said his name then said no this guy slightly different.
So did NARUTOS chakra sig change or gai knock a few screws out of madara?

May be latter

 

[GloriousTrainwreck]

I'm guessing his chakra became different to him. Like when Karin could barely recognize Kabuto.

 

[Chīkara]

Its due to the Rikudo chakra.

 

[Sjhsgjhsgjshjshjsh]

Just like kiba felt the changes in naruto when he went kcm.