Kvasir gave you the final test to join the Fangs. First you slaughtered the Brohums in Brusthonin, then you fought the Defenders in the Eye of Reshanta, then you brought down the Dredgion by killing one of its two captains. After undergoing High Priest Balder's final blessing ritual, you finally joined Fenris' Fangs. And there was much rejoicing.