The note you found says the Razormane have burrowed into the Thousand Needles for some sort of unseen ritual. Raging storms and rising tides... The quilboar must be using some cruel sorcery they learned from Hirzek, a shaman who went to great lengths to twist the elements. If they plan to flood the canyon, this would require devastating elemental powers. We are ill equipped to deal with this, but a powerful shaman like you must have an idea. Return to your allies and see if you can't find an answer.