It doesn't have any deep philosophies or enlightening lessons. It's more of an autobiography in nature. A story about the life of the last Shadow Slave. A narrative following the adventures of a man that by all means should've been a the final villain if not for a flaw of himself. 

It's a beautiful story. Sometimes it features horrors beyond my mortal comprehension. Sometimes it's as sweet as sugar. Other times it's gritty and dark. But all in all, it as an amazing story. It's worth every second you'll spend reading it. 

The psychological aspect in this novel is better than anything I've read in any other harem genre novel. The psyches of the characters are extremely well written to the point that you can tell the author knows the human mind VERY well. Almost a bit TOO well. It's not something you'd notice if you don't have an eye for it. A normal person may even say I'm looking too deep into this. But let's just say I'm an fairly skilled on the topic of the mind. 

Although other aspects of the novel aren't as extremely well written as the characters' persona's, it's pretty decent. Very readable.