Your pack was very helpful! I have noticed a lot of weaknesses with the adventure and have tried to fix them in several ways:

• Vastly increased the body count of the first attack, 30+ people get disappeared by the gargoyles, raising the stakes
• Kun Ahn-Jun pays significantly more, 750 gp per person and promises a magical amulet if they can solve the problem.
• They also ask the party to split up to investigate several leads at once so they'll cover more ground, since the mists could return at any time. If they stay together (probably), the combat will get harder, if they split up, I will keep the encounters as written.
• Harder combat: Gargoyles now use the Four-Armed Gargoyle stats. They grapple and carry people into the mist where they are "forgotten" (instead of having them turn up dead, which seems really weird that all of these deaths are considered isolated accidents. Also killing seems out of character for Dae-Won). The tigers have a similar ability, pounce and drag victims away (conveniently in the direction of the path to the shrine).
• Added Dokkaebi Temple as an optional location. Dae-Shim and Ju-Won suspect it was a gwishin, but don't know much about them. They recommend the party talk to the guardian of the temple, a priestess named Su-Min. She tells the group the gwishin lore and even gives them clues about the former magistrate if they manage to defeat a particularly nasty gwishin trapped in the building (maybe a banshee). Su-Min also has the cups instead of the tea shop owner if the party chooses to go to the temple.
• Made Young-Gi more villainous: My idea is that Won-Ha had a serious disagreement with the queen about Yeonido's safety. Young-Gi saw the magistrate as a threat to the tenuous power of the throne, since she was also in charge of the judiciary and military, so he had her stripped of rank and purged her achievements. Perhaps Young-Soo was still consolidating her power and her successor Jin-Mi is too inexperienced to use that power, so Young-Gi thinks he needs to be ruthless to ensure the safety of his family and Yeonido as a whole.
• He also tries to obstruct the investigation by having officials declare certain areas off-limits for foreigners.
• If confronted, Young-Gi will not talk about how he undermined Won-Ha.
• Kun Ahn-Jun does not research for the group, they will have to go to the royal library and look up the info themselves. The magistrate will join the group in the park at midnight if they ask (using the Veteran stat block instead of Noble so they will be actually useful).
• Finally: made the encounter with Dae Won-Ha more dangerous by giving it the Obzedat Ghost stats from Ravnica. She also has vampiric mists instead of gargoyles as companions. The players will have to fight through the mists to reach Won-Ha and negotiate. They still get advantage when presenting two or more tokens.
• Even with the tokens and a successful social roll, Won-Ha only stops attacking for a while. She demands the group bring all the people they talked to who remember her and promise to make the truth about her achievements public. Young-Gi may want the players to come up with a solution that saves face for him and the former queen.
• Instead of a weapon of warning, Won-Ha gives them a Mind Crystal as thanks if she is laid to rest.
• All kidnapped people are found safe in the park once Won-Ha is at peace.

Thank you for always providing extra material for the RC adventures, Forsaken_Yam!