Board Thread:Naruto Discussions/@comment-24847491-20140921145042/@comment-24519434-20140925014608

Sage trans isn't Sage Mode because during Taka's fight with Killer B Jugo replaced a good portion of Sasuke's chest with his own flesh. But against Obito (as a Jinchuriki) he used Jugo to gather natural energy to mix with his Susanoo. Sage trans would have taken over due to the Natural energy at some point especially if it was concentrated around him. This was a Psuedo-Sage Mode (as he was using Natural energy) but Sage trans never even hinted at appearance.