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 neuromancer books. When someone had specific cybernetic augmentations (such as razors underneath their fingernails), they were considered "Steppin' Razor."