Deathstrike is an elite Klingon military unit.
History and specifics
Deathstrike are the fiercest guerilla fighters within the Imperial Marines. It's a super-elite force that consists of exactly 258 Klingons, which lives only for training and battle. Six of them are assigned on a rotating basis to the Emperor's personal guard. The others are ready, to mobilize on a moment's notice, from the spaceport on their private island on the penal colony world Slivi.
Once a year, the best among the Imperial marines compete for the privilege of being selected to be one of the 750 Klingons who are dropped onto the island via gravbelts. During the "six days of death" exercise, the island is defended by the Deathstrike who are outnumbered three to one by the intruders. Casualties among the defenders are filled from among the ranks of the surviving attacking force at the end of the exercise. It's the only way that one gets recruited into Deathstrike, and it's also the only way that one gets "retired". (FASA RPG module: The Klingons: Game Operation Manual)