It is Sasuke—the "genius" shadow—who saves the day. Using his last ounce of strength and the only trick Isshiki couldn’t predict (the Replacement Jutsu with a simple shuriken), Sasuke switches places with Naruto at the last second, allowing Kawaki to land the sealing touch.
is not a celebration of the old generation. It is a passing of the torch, burned and battered. It tells the younger generation (and the audience) that their heroes cannot save them forever. Eventually, the proud failure must finally fail. boruto 218
Not a battle cry. A scream of pure, helpless terror. The episode’s title is a direct callback to Naruto’s childhood. He was the "Number One Proud Failure"—the kid who failed the graduation exam three times but never gave up. That tenacity was his greatest strength. It is Sasuke—the "genius" shadow—who saves the day