Rune Priest

We are totally not psykers! The lightning you see is our animal spirits helping us! Its all true! We swear on our wolfy wolfs!

Rune Priest are fucking Librarians of the Space Corgis and their existence is one of the most infuriating for those who despise the fucking yiffers. Part of the reason why is because of the notion that the closet furries have a particular hate boner for psykers, especially the Thousand Sons, and are known to treat psykers with suspicion and mistrust. As you can imagine, during the burning of Prospero, Magnus pretty much went, "What the absolute Fuck on Tizca's Tip, Russ! You hate our people for who we are and yet you yourself use psykers in your ranks!?", to which Leman promptly rebutted, "You betrayed the Emprah! FUCK YOU!""

Thing is, the Rune Priests use shamanic rituals to avoid being sucked into the Warp. Totems and runes allow the Rune Priests to exercise caution and precision with their powers, but they know damn well to watch out for psychic predators and know their fucking limits. The Thousand Sons are reckless and self-indulgent with their powers. They consorted with daemons even before Magnus singlehandedly shattered the Emperor's design to utilize the (much safer) Webway. The Wolves don't hate the Thousand Sons because they're psykers; they hate them because the Vlka Fenryka had been fighting monsters and uncontrolled psykers since Russ was found, possibly including the two missing Legions, and the Thousand Sons gleefully charged down the path to damnation while treating the Space Wolves and everyone else like idiotic barbarians, and then acted like victims when their hubris and Tzeentch conspired to bite them in the ass.

Anyways, like the Librarians of Codex Chapters, Rune Priests are combatant psykers, using their psychic abilities to aid their brothers on the battlefield; off the battlefield, they are the keepers of the chapter's librarium and store of knowledge. The major difference is that Rune Priests do not believe their psychic abilities are derived from the Warp, but rather from the animistic spirits of their homeworld, Fenris; which is channeled through totems and runes on their armour, which as you can imagine, is fucking bullshit and is just more excuses for the Wolves to say, "Nuh-uh! Erh Meh Gerd! Des Tertelley Nert Psykers At All!".

There does seem to be an element of in-universe discrepancy on this: In Thousand Sons Ohthere Wyrdmake and Leman Russ say repeatedly that the Rune Priests did not use the power of the warp, even while accusing the Thousand Sons of corruption at the Council of Nikaea. However, in Prospero Burns Helwintr and Russ don't even mention this bullshit. The Space Wolves are not the savage ignoramuses that they want everyone to believe they are and seem to have a perfect grasp of the situation and can clearly differentiate between psyker and sorcerer, which is conveniently compatible with what will happen after the heresy. But the Thousands Sons seem to fall for it, so in their eyes, that fact that the Wolves would utter this kind of stupid nonsense is somewhat believable.

None of which changes the fact the Space Wolves have either deluded themselves or are lying to everyone else about where their own psychic powers come from, making them either idiots or hypocrites respectively. Also, if you think about it, their excuse for their hostility makes it even more hypocritical: they're just enjoying doing what they've always did and glorifying their burning of Prospero by pasting a lame "It's not personal, it's because you 'hindered' the Emperor, no wait, that still sounds too tepid... I'm just going to assume YOU BETRAYED THE EMPRAH WITH FULL MALICIOUS INTENT LIKE THE OTHER TRAITOR LEGIONS!".

The discrepancy between the depictions of "ignorant savage" vs "lying hypocrite" is addressed somewhat in Wolfsblade. The Rune Priest traditions were descended from the shamanistic rituals of Fenris's native tribes, and have remained unchanged for countless centuries. Russ and Jaghatai Khan both use "older traditions" which shielded themselves from corruption from the warp by limiting the power they draw from it; they acknowledge both the power of Fenris and the Warp side-by-side and Russ even takes a jaunt into the Underverse (essentially a sanitised version of the Warp) to find a means for defeating Horus. Because of this, Russ is flat out called a hypocrite by Rogal Dorn (who coincidentally was the only Primarch who still adhered to the Edict of Nikaea at that point) who points out that there are no limits on power and Russ begins to wonder if he really was a hypocrite and privately resolves to examine his Rune Priests' relationship with the warp at a later point. Whether he actually did this or not is anyone's guess.

Chapter Role

Rune Priests preserve their Chapter's entire history not in written form, but memorize it in great sagas. A Rune Priest who begins his training as a Skald is usually assigned to a single Great Company where he is taught its tales. With every new Great Year he joins another Company until he has learned the Chapter's full history and can be sent to whichever Rune Priest needs an apprentice.

The basic weapons of the Rune Priests are their psychically charged Runic Weapons. A common power among Rune Priests is the ability to summon storms across the battlefield which can cover the army's advance. Furthermore, they can cast runes which predict the ebb and flow of future events. These runes are usually carved from the bones or teeth of totem animals.

Many Rune Priests are psyber-linked to cyber-ravens, which are known as "Choosers of the Slain" to the Space Wolves. Their link enables them to see through the ravens, eyes and control them, thus allowing them to use them as scouts and messengers.