Deathleaper

Deathleaper is a Lictor of Hive Fleet Leviathan, a hunter-beast that the hive mind has refined into a specialist assassin of key enemy personnel. It does not engage armies directly. It kills the individuals on whom their operation depends, one at a time, and leaves the surrounding population to anticipate the next attack.

The clergy of Saint Caspalen were the first to encounter these methods, and other warzones have encountered them since. A Lictor is by function a scout, and Deathleaper applies that role to targeted killing. The Munitorum, the Imperial administrative body responsible for supplying and organising its armies, refers to Deathleaper in the present tense, as past-tense references have not held.

The hive mind has no requirement for a singular champion. It requires a specialist capable of unsettling a world before the first wave of the invasion lands, and Deathleaper fulfils that requirement.