There seems to be a bug in the Hall of Darkness. When trading ability points for attribute points with Moloch, which should be a 1:1 trade according to his dialogue, I actually lose 3 ability points to gain a single attribute point.
I tried again when I only had one ability point available, and this was Moloch's response:
"I'd like to help you, my friend, but unless you've got a mark of Ability to spare, no deal can be struck."
