The only logical reason for deviating this much from the novel to create something this badly written is that the manhwa finished earlier than the novel so the creators of the manhwa didn't know the ending of the novel. The outcome is superficial, mediocre and anticlimactic. They even made K a victim, LOL. If they did it deliberately, knowing the novel, they are not just talentless but plain stupid too.
The only logical reason for deviating this much from the novel to create something this badly written is that the manhwa finished earlier than the novel so the creators of the manhwa didn't know the ending of the novel. The outcome is superficial, mediocre and anticlimactic. They even made K a victim, LOL. If they did it deliberately, knowing the novel, they are not just talentless but plain stupid too.