Quest to gain pages from the Black Book of Salt and Ash. Each page can be used to add a stackable +10% attack modifier to the currently wielded weapon. The spell lasts 30 minutes.
Hassha tells you, "Hassha grants you leave to enter the Cells of the Black Book, human. Tread carefully, but rejoice! Great power lies within. You must take it, and use it... Let it be known, the portal will only accept you if you have given yourself to blood and darkness. You may only enter the Cells of the Black Book if you seek the blood of your fellow humans..."