The end of the game is very unexpected, because you will find yourself in front of a very difficult choice. You will have to either kill your cousin Constantine or join him. Moreover, the final outcome of the entire enterprise will depend on your decision.
So, if you decide to join Constantine, then, alas, you will have a bad ending. First you have to fight Nadaig Baro. After the end of the battle, Constantine will say that he does not want to kill you. Moreover, he will tell you what goals he pursued and reveal his secrets. After that, he will offer to join him. If you agree, your character will cut his palm and hug his cousin. As a result, your decision will lead to a rift between the characters, and the whole world will be engulfed in endless conflict between the parties.
If after the last battle you refuse to join Constantine, then the ending of the game will be more rosy, with the exception of the death of the cousin himself, of course. The main character will kill Constantine by driving the blade straight into the chest. As a result, the decision you make will have a positive effect on all characters. For example, Alfra will lay down her arms and begin to explore nature, the lands of Tir-Fradi will again be filled with living creatures, and the number of patients with malikhor will significantly decrease.