The Etebeans, in their earliest pre-history, gave the force of Entropy an anthropomorphic personification which became a deity to them. After their civilisation developed they further developed their religion by adding a creation myth that this deity had lived in a world before our own which had been in a state of eternal war until a horrifically P-Oed female warrior named NuhG’waq Ter, in vengeance for her slain mate, ended the war by slaughtering everything (the whole salting fields, searing the lands, apocalyptic rage sort of thing) before she gave birth to our universe, dying in childbirth. Her subsequent death and mother hood brought her an enormous sense of peace, transforming her into Marwolaeth. Separated from her children in our universe she desired to be reunited with her new family so she gave the world the gift of death as a means of granting us the same post-death immortality she had. The Etrebeans added a full pantheon of gods and goddesses, all of whom were entirely killable, in keeping with Marwolaeth's desire to eventually be reunited with her children. The only creatures exempt were the Sun King, an anthropomorphic personification of humanity's collective evil, and the dragon Kul Katura, a similar anthropomorphic personification but of humanity's wisdom, neither existed before humanity but rather were borne of it. (This is also why the Wolvesh have no use for gold as anything but a bartering tool with other nations, theres a whole myth about how the Sun God gave it his radiance, thus causing it to become cursed, while silver is viewed as a holy metal due to it's association with the moon, being Marwolaeth's gateway to our world, hence the Wolvesh' dedication to preserving the moon and only allowing underground colonies.)
After the Etrebean Empire fell through a combination of a plague and the corrupt, hamfisted self-preservational tendencies of the elected senate (basically they sequestered themselves away in country estates like Prince Prospero and diverted supplies from the cities, which increased the death tolls further. The survivors abandoned the cities and became the 25 tribes of the Wolvesh.) the other gods were 'killed off' but worshipped posthumously. Meanwhile they added the concept of Ravenbrook, a replica of Wolfsea's forests, as an afterlife in the world-before-the-world except it had no sun and was lit by bioluminescent plants.
Modern Wolvesh still believe in the existence of Marwolaeth and Ravenbrook but belief in the Sun King and the other gods has waned considerably and since there's never really been a concept of an organised, planned-out universe so they're not into crazy crap like creationism but yeah, you can pretty much summarise them as death-worshippers which, considering their entire culture was borne out of the period when they were warring tribes and they've only really grown out of that through unification around 1200 years ago, pretty much makes sense. Their code of honour is pretty much a result of a melding of their tribal culture and their religion (Theres no actual posthumous reward, more that they leave behind a good legacy to those who are still alive and have yet to be born, the Wolvesh take family very seriously.) but yeah, that's basically ti in the smallest nutshell I could find.
