Yeah, never heard of them. What's the series about?
Basically it's about three people, when reunited will be able to revert the universe and prevent demons from controlling everything. However, when the three people are reunited, they experience the power it gives them, but are to scared to use it. This allows thousands of demon to cross over and massacre million until, there is a final battle.
That is it super summarised, however, it spans over 10 books, with around 300 in each, so not that long

. Plus I loves how it depicts people being ripped apart.