Sakura really went all out trying to save Naruto, and my heart was pounding watching Minato struggle to seal the Nine-Tails into him, only for Black Zetsu to just pop up like that. I couldn't believe how suddenly the stakes jumped with both Naruto and Sasuke on the brink, making me kinda frustrated that Minato couldn't pull it off quicker, especially knowing what we know about Zetsu's true nature now.