My last post showed my work on thunderwolf cavalry. I love the fluff and feel of the Space Wolves, but I've always felt a need to take my own spin on things. So the Blood Wolves came about. With dark grey and red armor (and overall paint scheme), and unlike their SW forbearer the Blood Wolves come from a world that isn't continually locked in a winter. Their world is covered in mountains, forests, and rocky wastes, interspersed with areas of agriculture. The people of their world are a mix of Japanese, Norse, and Scottish decent. And the various peoples intermingled and also segregated from each other by the harsh landscapes and extreme ferocity of the native wildlife.
With these ideas in mind, I began working on how I'd work those cultures (fallen back to medieval technology overall, and a little black powder mixed in) into a Space Wolves successor. Firstly I decided that the chapter was founded in the 36th millennium, as an experiment in stabilizing the Space Wolves geneseed through mixing of select zygot into their founding. And while it seems to have helped for some time, it had drastic effects after the first millennium. The Wulfen 'curse' began to become a rampant issue, and a high percentage of aspirants to the chapter had to be culled. Even after making it through the early stages of being a Blood Wolf, many would fall within the first century to the curse.
This genetic curse has caused the Blood Wolves chapter to routinely be at under 400 full Space Marines. But this wasn't the only trouble the Blood Wolves have had. During the 39th millennium an Ork Waagh! instigated by Dark Eldar caught a Blood Wolves crusading force unprepared. Half of the Blood Wolves fleet assets were destroyed before reinforcements could arrive to extract the remaining Battle Brothers. Over the next fifty years a number of Dark Eldar strikes crippled a large portion of the remainder of the Blood Wolf fleet, leaving the chapter with their Battle Barge, a Strike Cruiser, and 3 Sword class Frigates as the full remaining space forces remaining.
The Blood Wolves finally tracked down the base of the raiders who had systematically reduced their power and ability to project force in the Eastern Fringe (where they were located). The remaining might of the chapter fell on the small moon that housed their facilities, and over the course of several weeks every member of the Dark Eldar Kabal involved were reduced to corpses. The Blood Wolves hadn't been unscathed though, and nearly 100 brothers died from the various poisons and deadly xenos technologies used in the campaign.
It took nearly 500 years to regain their former strength, as they couldn't remove themselves from obligations across the region they protected. By the late 40th millennium the chapter had risen to an unheard of for millennia 437 battle brothers. Unfortunately (in the minds of the chapter battle brothers) for the chapter nearly 9% of the brothers showed signs of the Wulfen curse. And of the two dozen dreadnaughts the chapter had in the first millennia of operations, only 9 remained. The fleet had grown through the reclaimation of a pair of frigates from renegades, but this did little to alleviate the massive losses of the previous millenia.
On the bright side, the chapter had managed to keep much of their industry untouched within their battle barge. Land Raiders, Rhinos (and their variant combat vehicles), as well as Terminator armor were in good supply. And over the many hundreds of years a fair number of battle brothers had become pack brothers to the Blood Wolves of their homeworld (Biologically they are so close to Fenrisian Thunderwolves as to be a total fluke), as well as several large packs of the lesser Wild Wolves becoming like brothers to the Space Marines.
The rune priests of the chapter use a mix of techniques drawn from their homeworld to foresee events, as well as primal 'spirits' and forces in combat, much like their distant Primogenitors. Oddly enough, the Blood Wolves aren't sure if they are geneseed decendants of the Space Wolves, but they truly don't care one way or the other. Several outside observers have noted they structure theirselves much like the Space Wolves, and have many similar customs and traditions.