I have defeated the 3 fang banshees and the fang guardian twice each, with congrats from Shalek, but no sul dust! What do I have to do to get soul dust, other than solve the riddles and kill the bosses (twice)? Please help?
This is confusing. I just went through there again today. Once you complete the quest to get the fangs and the rubbing from the obelisk you go do other things. Somewhere in there you collect the 12 statuettes. Later you're told to go talk to Shalek. He tells you to go back up into the Vault of Ice for the soul dust to light the braziers. This is the confusing part. When you go through the Vault door, do not talk to Shalek again. You end up doing the first quest all over. Check your quest arrow, it's probably on the wrong quest. Correct that. You have to fight all three girls again, but under where it says "..a puzzle appears", this time it will also say "collected soul dust". When you've collected dust from all 3 girls you're told to talk to Shalek OUTSIDE the chamber down in the entry hall. Don't talk to him on your way out. Go downstairs. That's when he tells you to set out the statuettes and light the braziers.