Under the leadership of Leman Russ, the Space Wolves Legion began to change, to become a hybrid of Fenris’ unforgiving way of battle and the patterns of Imperial military doctrine that had gone before. This new Space Wolves Legion was truly a refection of neither of those parents, but something new entirely, and the increasing use of so-called Grey Slayer units was perhaps one of the most visible outward signs of this transformation. The Grey Slayers were, in effect, compact individual warbands of Space Marines, all but autonomous in their own right in the field: fluid, sure-footed and largely exempt from the reliance on direct commands from above. They were expected to deal with myriad challenges on their own if needs be, and above all to close with the enemy on their own terms; to seek and destroy.