Two words: annoying, and depressing.
Act 9 is obviously made to a be tearjerking moment. So many characters close to Cricket and young Jinsoyun died. And their deaths were for each other:
-The Lyn boy died cuz he insisted staying until Ryu was "saved".
-His sister died because she shielded for Jinsoyun.
-Jinbin, the Jin boy died because he stopped his master from committing a crime for their sake, thus angering Mushin.
Yeah, the act is sad. The final mourning scene was heart-breaking However, coming hand-in-hand with this depressing feeling is the feeling of annoyance.
Why it is annoying? Because, once again, the story writers select a way that I believe every player hate to resolve the story: portraying the incompetence of Cricket, the player's character. For the sake of drama, writers make Cricket super naive that never learns a lesson, turn him/her into a betrayal-magnet where there are at least a betrayal per Act, and push the cutscene incompetence to maximum despite of being the current Master of Hongmoon School. To make it worse, the writers also create some loopholes to the story, making the whole act become unbelievable dramatic.
Let me tell you my thought as I progress through the act:
-The thing with Sacred Beast's Heart to prevent your death in future: this is kinda random and out of nowhere. In very early acts, the player had to travel in the whole Moonwater Plains, asking to receive Sacred Beast's Chi to counter Mark of the Black Rose gnawing their body. In this act, some rich boy suddenly owned a Sacred Beast's Heart and was happened to be conveniently near you, and you easily got that "supposed-to-be-super-rare" item just by winning three fights. I think this act was just an excuse to re-introduce the successor of the Eight Master (still 7 cuz no one successes Zulia).
-Bringing your disciples to a dangerous territory: yeah, as if the enemy won't think about taking them hostages. Maybe it can be explained that leaving them behind make them vulnerable to attacks, like what happened when Cricket left them behind to help Poharan and they got attacked by Zulia. However, Cricket can just ask someone to take care of his disciples instead of making all of them facing dangers, in which these disciples would become certainly dead-weight.
-Getting phantom gripped, AGAIN: like, every 3-4 acts, your character gets phantom gripped. EASILY. Lusung phantom gripped you (twice, in main story and BT-raid story). A random pirate Force Master phantom gripped you. An Ebondrake ASSASSIN phantom gripped you. Why the heck is Cricket so easy to get Phantom Gripped? Is he/she has some kind of magnetism mechanism built-in and attracts all kind of phantom force? Why don't enemy just chain Phantom Grip the helpless Cricket to their base, lol?
-Jinsoyun refused to participate in any fight during their runs: when you lead your disciples running away, you may notice that Jinsoyun did not help to fend off enemies. While she is a delicate girl who is prone to be Damsel in Distress, she is a freaking DISCIPLE of Hongmoon school. You spend YEARS to train her and other disciples about martial arts. You even saw cutscene of hers practicing with a sword. Even Jinbin who started to learn at the same time as her can fight properly. But no, you now have a complete dead-weight. Yeah she is cute, but it seems every misery of Cricket comes from her, both adult and young version.
-The Lyn boy nagging to stay behind until Ryu was rescued so that they could leave together: While his reason was understandable, he failed to realize that the whole group was in a deadly danger that can cost everyone's life.. Well, he was a child - a pretty aggressive one too, so that may be the reason. However, the biggest failure here was Cricket, who was so push-over to listen to a child's rant and go along with it. This shows that Cricket has zero dignity of a Master and the disciples treated their Master like a powerful friend. Supposedly, as a Master, Cricket should have denied his tantrum, tried to send them to true safety first before searching for Ryu. If the boy did not listen, just gave him a punch to the guts, or a slap to a face so that you can shut him up. He may still die later cuz I can imagine him running off on his own and got caught, but at least, Cricket actively tried to prevent it.
-Betrayal: yeah, the recurring theme of BnS: Revenge - Naivety - Betrayal - Forgiving . Not surprised when it happened from Ryu, since he was clearly fishy. And Cricket never learns to doubt, as usual.
-Yunma Fei came to aid: A super biggest loophole: First, it was her who warned us to not come to the enemy's territory, then she came to the enemy's territory herself. ALONE. WITHOUT ANY TROOP. Yunma Fei was no fool. She was a leader of the Resistance force when Jinsoyun was still in power. She was smart enough to have a double during act 3, and she pretty much avoided her death in that act when Yura attacked her double. And that girl went straight to danger without giving a thought. Talking about skills, while Yumma Fei can at least protect herself, her skill looks like to better than just a random Stratus Soldier at best. Heck, I think even a random Ebondrake assassin can kill her easily. She is definitely someone you don't want to meet within the enemy's playground, when you already had a bunch of children to care for. If would be more better and logicial, if she sent her elite body guards, either Junghado or Yu Chun (I prefer Junghado, because he had experience of traveling) to help, as they are clearly more skilled than Yunma Fei herself. She may still get caught because Cricket opened the darn Dragon Pulse that lead straight to Zaiwei, allowing Stratus Empire to directly attack the palace and take away the Empress. Sound a lot more logical than she tried to solo the thing.
-Namsoyoo: figured that she was here cuz her bloodline was important. At least, she served to make the Status General an ally to Cricket. When looking at her, I missed Gwon instead. Ironically despite of being sought after as a sacrifice and super helpless, she outlives everyone.
-Crickets unable to protect Lyn girl and Jinbin: okay, the first might happened too fast for Cricket to react. However, the latter clearly happened long enough to do so. Cricket had plenty of time to jump between Mushin and Jinbin to take the hit aiming to kill the boy. But no, the best Cricket could do was reaching hand to the air, helplessly looking at the enemies slaughtering his disciples. This happened TWICE in a single cutscene. Even if the boy needed to die, at least he died while his Master tried to protect him instead of just standing there like a incompetent idiot.
-Mushin's whole plan behind the scene: one word - STUPID. If he gets the Twilight's Edge and Namsoyoo as sacrifice, he already has enough things to make successful Heaven's Mandate. But no, let be more evil, take Cricket's disciples as hostages, make Cricket feel helpless and miserable, and nearly risk to fail the ritual if his blood isn't qualified. The last part is important and stupid at the same time. If his blood is not qualified, then it may open a gate to Demon Realm and wreak havoc the whole Dasari Palace, like what has happened to Necropolis in Moonwater. Actually, that would be a better ending cuz at least we can see Mushin's being failed after many of our disciples have died. Jinbin's death would have a more significant meaning. But no, Mushin must be a favourite villian, so writers make him succeed by luck instead. Yeah, it was by luck he discovered his blood work too, but it trivialized the role of Namsoyoo as a necessary sacrifice, making Jinbin's death just another death, and make you wonder if he is actually a smart mastermind, or just a lucky villian.
Edit; Add my rant about Phantom Grip used too frequently in the story.