"Liam, even though we aren't good people, there's one thing that you need to understand."
"There are people in this world who are fragile - like flowers. While our souls are darkened, we make sure that those people don't turn out like us. They're the reasons why this world is not as despicable as it should be."
Liam is a bad person - a member of a long lineage of demons. However, it was his mission to keep an innocent soul - a flower - pure, even when his was black and dirty as coal. He found his flower.