Memory drugs huh? As little as the author likes to overtly reveal the motivations of characters, the actual reasons for their actions can be surprisingly shallow. Goomoonrong getting injured in this fight isn't bad, but I feel like it would be more impactful if siwoon killed off some of his new subordinates. There have been multiple cases throughout the series where goomoonrong or the another antagonist kill a master opposing them, but are only driven away from completing their goals by some plot device or loss of an item. They don't actually lose anything though; they just get delayed. Really looking forward to a genuine mud-in- your- eye moment. Would do wonders for the plot.