User blog comment:Halo1081/Chapter 128 and forward/@comment-4911196-20150302030909/@comment-25993554-20150302040021

Going by logic, Nagisa wouldn't be reluctant to strike first, but he's a hitman, not a fighter. If his first attack is unsuccessful, he's done for. If he's dragged into battle, he's got few options left.

His clap stunner works on most people, as long as he can read their wavelengths. Given that she kept her true self hidden from him all along, he might not be able to do it.

Tentacled beings have enhanced speed and reaction time, so it would be difficult for him to take her offguard. And since she's trained with the class the whole time, nothing they can do will surprise her. That was the class's only upper hand against the God of Death, and we know how that battle ended.