SOLUTION OF THE PROBLEM

But anyhow with the help of Olga they are able to defeat the invisible army of Lord Alloces and as soon as his army is destroyed he too diminishes along with army of invisible and everything perishes from there which shocks everyone and now it seems like nothing has been here ever and soon the dark place transforms into a light one with everything around them turning into a totally different world which seems like a fairy land and amazes them 

And soon they come across someone who appears before them who is an Angel, and she is happy that saviors freed her land from the dark powers of Lord Alloces who is also slave of Lord Icarus and is selected only for the protection of "Book of Wisdom" as soon after Demon Lord Icarus got the books he started attacking various species and making them his slaves and hence giving the responsibility of protecting the books