We Should Kill Him First (殺しておくべきだ, Koroshite Okubeki da) is chapter 684 of the Naruto manga.
Sakura realises that Obito was willing to die so easily because he was beyond saving but soon casts aside these thoughts when the Uchiha calls her, and Naruto's clone forth. Though Kaguya notes their presence, she pays little to no attention to them on the battlefield and instead opts to attack the real Naruto. As Naruto contemplates his next course of action, he settles on a combination of diversionary tactics and taijutsu. Kokuō lends Naruto support with its steam-based ninjutsu bolstering Naruto's physical attacks to monstrous levels. Shocked that she was being pressured in her own dimension, Kaguya emerges from the rubble to find herself surrounded by a barrage of shadow clones. Assaulted from all sides, Kaguya is forced to retreat to another dimension — an opportunity which Naruto and Obito take to invade her dimension. Sensing the invaders, Black Zetsu advises his mother to kill Naruto rather than give him the opportunity to reunite with Sasuke and seal her. Though hesitant at first, she ultimately agrees with this advise and uses her All-Killing Ash Bones technique which strikes Naruto and begins to disintegrate his body. Believing that now the clones would be gone as well, she returns to her ice-clad dimension to find the clones still there much to her shock. Meanwhile, Obito and Sakura invade her main dimension, intent on finding Sasuke.