The spell blaat doors says it cost 35 nora. However, it spends all of the nora you have in your nora bank. Casted blast doors with 100+ nora in the bank and 3 doors out, ended up autodropping the amount of nora I had to 0. Edit: It drops 35 nora from your bank for each door that you blow up. So two doors uses 70 nora, 3 doors uses 105 nora, etc.
Makes it so much easier to kill AA and SotM. I just wish it didn't have such a huge unintended drawback.