Lucifer was thinking about how the newcomers would have to kill people for 30 days straight before they can be admitted to the Warmester Denoble House fully.
He was thinking about how ugly it was for the Warmester Denoble House to do something like this, but well.
This was just how life is for some demons, and it is something Lucifer considers normal as well.
However, just because Lucifer considers it normal doesn't mean he likes the fact that people are being forced to kill.
In fact, he hated it since this was something Lucifer didn't really like as a man.
Of course, Lucifer is a hypocrite, and he has done things worse than this and he knew that very well.
However, Lucifer didn't care at all about being a hypocrite, and he just really found this custom of the Warmester Denoble House ugly.
However, it seems that he couldn't think about this anymore as Rouge spoke once more, causing Lucifer's attention to go towards him.