–Lucy, in Chapter 1, arguably at her most ruthless
Lucy's murder ofKurama's awkward, nerve-ridden secretary Kisaragiis not the first killing seen in the series, nor even the most gruesome. But in both versions of the series, it brings home as little else does the utter ruthlessness of the main character and protagonist.
As the lead-up to this scene begins, the narrative shows us how out of place Kisaragi is in this environment of lock-down, danger and weapons both mechanical and psychic. In the middle of an emergency with blinding lights and blaring klaxon alarms, her focus was solely on a cup of coffee for her boss, again while soldiers arm for the fight of their lives which many will lose. A bit of a fake-out may have been in play here. In many narratives, and especially in manga/anime, such a character as Kisaragi would find themselves protected by dumb luck and their lack of awareness of their peril: Kisaragi was not to prove so lucky.
In the manga, Kisaragi merely walks by Lucy, who then seizes her and holds her as a hostage. Acutely aware of what Lucy's escape would mean to the world, Kurama sadly informs Kisaragi that she must die to prevent this. Lucy, both seeking to negate their plans to stop her and taunt Kurama, with whom she had a history, decapitates Kisaragi, almost seeming to lift the head off her body. As her escape by other means opens up, Lucy verbally taunts both her victim and her target.
In the anime, Kisaragi stumbles into Lucy's path. Lucy may or may not fully realize she has value to Kurama, and instead of an attempt at hostage-taking, Lucy merely twists her head off, the sound of tendons tearing being almost audible. In both versions, Lucy then uses Kisaragi's headless body as a distraction and a demoralizing sight, suspending it in the air as it takes fire, her abilities turning back the bullets as it had before. Kisaragi in both versions seems to die so quickly; her unawareness persists unto death.
Gruesome in both versions, this is without a doubt the first instance seen of Lucy murdering a complete innocent. Kisaragi can present no threat to Lucy, does not know who she is, and can not have played a part in her imprisonment. Even if every last guard were a vicious sexual predator and even if Kurama and company had given this girl her strange powers and her horns after kidnapping her, Kisaragi's killing by Lucy was for the worst of reasons: vengeance, and because she could.
The murder of Kisaragi is the harshest, most direct early indicator that while the protagonist may have her reasons for being how she is, she is not necessarily the hero of the series and that predicting who will live and who will is not a safe bet, and very possibly a fool's errand.
I'm sorry, Kisaragi. But you just watch. This isn't the end. I'll definitely have revenge.
–Kurama, swearing over Kisaragi's remains, ignoring the old warning to be careful what you wish for