This power thing is not hard to understand. Lucifer's assistant name is literally No one. His name is 'No one'. But he pops up every now and then usually when I lean something new and will explain it. Turns out you don't have to say the words just think them in a certain way.

I have learned how to summon my book for names of souls I need to collect. The book is black leathered with beautiful designs in it and in the middle of the cover is a crow head it eye is usually closed but if I summon my book I can make it open. And it'll tell me about a person if I ask it about someone by full name.

I can see names above humans, and age, death day. If they are holy that will have transparent halos above them. If not their a 'X' over there face. I can turn this power off if i wished.