Keiko
Keiko noticed two things. Firstly, the nearby staircase was blocked off by some sort of barrier, made of wind. Second, the enemy surprised her.
The ghostly figure ahead carried its sword like a seasoned veteran. Its refined stance made Keiko reevaluate whether this thing was actually the mindless monster it appeared to be from a glance. Haruna stepped forward with an expression like pure steel, her own blades at her side as the creature seemed to track her movement. It didn't pay any attention to Keiko, perhaps because of how far back she was standing.
Haruna stood around six feet away from it and then, she stopped.
So much time had passed since she'd left the Compound, that Keiko had genuinely forgotten what high-level fighting was like. Due to her time training Ash and Kaori, she hadn't been able to practice the higher proficiency strategies she'd learned lately.