Black Zetsu was losing his mind.
He had practically entered the anti-Asura deranged zealot mode. Emiya Shihara truly hadn't expected that perhaps his past performances had been a bit too enthusiastic. His earnest attempt to foster Uzumaki Naruto's growth as quickly as possible had actually caused Black Zetsu to mistakenly believe that he had once again fallen into one of Asura's verbal traps.
What was so great about Asura anyway?
Chapter 128