Board Thread:Episode Discussions/@comment-1251315-20161013111826/@comment-4646462-20161021070718

Gyuuki not contacting Naruto regarding getting captured is far from the only plot-induced idiocy that he is guilty of. He also failed to warn everyone about the Shinju (rather, the Tree Form), which if he had, lots of lives might have been spared.

As for Naruto not using full SPSM, he really dropped the ball in the Chuunin Exams assault. Not to mention, why shield the blast when Sasuke's right there with his Rinnegan abilities? He also might've felt confident in the final battle with Momoshiki (and rightfully so) to not pull it out (then again, who knows if he'd been able to with Gyuuki out of the count?) The Last is a different story; it's a combination of Kyuubi Chakra Mode and Sage Kurama Mode, and it was conceived before SPSM was even a thing.