Steppin' Razor
From Halopedia, the Halo wiki
Steppin' Razor is a Halo 3 multiplayer achievement. It is awarded for scoring a Triple Kill with the Energy Sword in a ranked free for all playlist.
Additionally, it is a reference to William Gibson's novel Neuromancer. A central character in the book had extensive cybernetic augmentation, including razorblades under her fingernails that could be extended and contracted at will. Later in the novel that central character, Molly, was dubbed "Steppin' Razor" by a secondary character.
