Nine Sols Let's Play: The Story of Yi Slaying the Nine Sols and Its Combat Design

The protagonist is a man of a cat-like race called the "Solarians." He was a member of the Solarian council and the one who devised a brilliant plan. However, after learning a certain secret, he became the target of an assassination ordered by the head of the council.

Gravely wounded, the protagonist is recovered by a mysterious being and wakes up 500 years later in a village of Apemen. The village holds a festival once every two years, and each time several villagers are chosen and given the honor of "going to the Sun." A child who looked up to the protagonist like an older brother has been chosen for this very festival.

The protagonist had planned to sneak into the facility during the festival. He originally meant to infiltrate in secret, but unable to abandon the chosen child, he ends up breaking into the facility to rescue them.

The narrator names the action as the game's defining feature. You deflect enemy attacks to build up energy, then attach talismans to enemies and detonate them. When your HP runs low, you smoke your pipe to heal. You repeat these actions as you make your way through the underground facility.

The first boss is a guard machine blocking your path. Since it's the first boss, its attacks aren't fierce, and the narrator explains you can beat it by reliably deflecting its big swings and slipping in attacks between them. All of its attacks in the first half can be deflected, but in the second half it mixes in red attacks that can't be. Landing a kick in midair against these knocks it down and creates an opening to attack. Because this way of handling them comes up again and again in later boss fights, the narrator considers this boss a well-designed tutorial.

The overall picture of the story is also explained here. The facility is actually a giant spaceship, managed by the Solarians who serve on the council. The protagonist was once a member of that council too, but, as shown in the opening, was betrayed by its head. The broad flow of the story is that he takes down the Sols of the council to restore order. The first battle, according to the narrator, is a scene where he fights the security weapons in order to get close to the man he was closest to on the council.

After defeating the guard, the protagonist reunites with the first Sol, Kuafu. This scene and the Kuafu fight are centered on dialogue and music, with almost no commentary from the narrator.

Next, he faces the second Sol, Goumang. The protagonist has just had a powerful arrow made for him, and the narrator says they'll test-fire it in this battle. The Goumang fight is shown briefly, straight through to the defeat.

The third is Yanlao, the Sol in charge of weapons development. Here you fight a mobile weapon that Yanlao controls remotely. Unlike the previous boss, it's a huge opponent, and the battle is depicted as footage seen from the control room. The narrator says it's nice that it "looks kind of like a game screen." Its attack patterns are simple, consisting only of grabs and body slams, and since the first three Sols can be challenged in any order, the narrator thinks it's probably positioned as an early-game boss fight.

Between battles, the Solarians' circumstances are explained. They originally lived on another planet, but a certain event caused a disease to spread across the entire planet. To buy time until a cure could be developed, they put their bodies to sleep to slow the disease's progress and continued dreaming in a virtual space. As a result, they have now been asleep for as long as 500 years, occasionally waking to perform system maintenance before going back to sleep. From Yanlao's point of view, he wakes up for the first time in a long while only to find a colleague who should have died 500 years ago coming to take him down.

According to the narrator, the council had grown increasingly corrupt, and many of its members acted on their own agendas. The protagonist believes this corruption brought about the worst possible outcome, and he is going around purging the Sols. Toward the end of the battle, there's a sequence in which the protagonist, who is well-versed in software technology and skilled at hacking, takes over the weapon and turns it against its controller.

The fourth is Jiequan. He is introduced as a military general who is also well-versed in genetic engineering and has been continually modifying his own body through drug administration. The protagonist planted poison in a device beforehand, so Jiequan, a man of combat, enters the battle already weakened. During the fight he can be seen coughing from time to time, showing that the poison is clearly taking effect.

From this battle on, you gain access to the "Unbounded Counter," which lets you charge up and then deflect an enemy's attack. You also obtain a charged attack that can break barriers. The narrator says these additions instantly broaden your combat options and make it endlessly fun.

In the second half of the battle, you unleash all the arrows you've been saving at once. This brings the enemy down to about 30% of its health. The narrator says the arrows in this game are tremendously powerful, perhaps because the protagonist's source inspiration is an archery hero. After that, just a little more chipping away finishes the fight.

The fifth Sol, Lady Ethereal, is the developer of the dream system that creates virtual reality. To meet her, the protagonist enters that virtual space.

The battle has three acts, and the first act is finished by using up all your arrows. From the second act on, clones of the boss appear, and trying to hit the clones only gets your attacks nullified, making it hard to deal damage as intended. This is where the Unbounded Counter comes in handy. The technique not only deflects attacks but also deals damage back to the real body, making it highly effective. However, the narrator explains that its drawback is that it requires charging and can't be canceled, so depending on the opponent's next move, there are moments when you can't use it safely.

The narrator emphasizes this push and pull as what makes the game fun. Even when an attack you can't handle might be coming, do you ready the high-reward Unbounded Counter, or do you play it carefully, always staying at a safe distance? The narrator feels that this subtle choice is what makes the combat experience fun. They also say that in games like this, the more stuck you get, the more strangely enjoyable this kind of gambling element becomes. However, they also note that some viewers may dislike it, so in the video they intend to stick to reproducible, safe actions as much as possible.

In the third act, a big attack comes first, but the opening right after it is large, letting you land charged attacks and more freely. The other attacks are mostly the same as before, and since the real body becomes easier to identify, the narrator sees this stage as easier than the previous one. There are also behavior patterns unique to this act, but they're a simple gimmick that only requires a kick. Once her health is low, the narrator finishes her off in one go at the next opportunity.

The sixth Sol, Ji, specializes in fortune-telling, and a roulette suddenly starts in the middle of battle. In this video, the healing effect was chosen. The narrator has never chosen the other two and guesses that something bad would happen.

Ji is immune to the disease and has apparently lived on in solitude as an observer of history. The narrator says that the protagonist has no reason compelling enough to kill him, but that he himself also seems to want to be freed from this fate of immortality.

In the second half, a troublesome move comes, so you first stop it with your bow. After that, the attack pattern is mostly fixed: a throw followed by three red attacks in a row. All of them can be countered with the Unbounded Counter, so the narrator suggests fighting satisfyingly by "making the gong ring out over and over," and says that the satisfying sound effect underpins the game's combat experience.

On the story side, it's revealed that Ji's unique constitution, immune to the disease, was intensively studied as a source of antibodies against the virus. However, it turned out that administering those antibodies to Solarians transformed them into grotesque forms. Developing a fundamental cure proved difficult, and time passed amid growing desperation. After the Ji fight, you proceed through an area where the remnants of Solarians from failed experiments run rampant.

The seventh and eighth Sols are the siblings Nuwa and Fuxi, who appear together. The older brother, Fuxi, suffered especially rapid progression of the virus, and after being given the test drug containing the antibodies mentioned earlier, his body has undergone advanced mutation.

Until now, the number of arrows was limited, but from this battle on you learn the ability to recover arrows through talisman explosions, further increasing your attack options. In the second half, you first fire off all your homing shots at once. You dodge Nuwa's attacks and handle Fuxi's attacks with deflections. While skillfully managing the siblings' coordinated attacks, you slip in talismans between them, building damage while also aiming to recover arrows. After that, all that's left is to keep whittling down their remaining HP.

Before the final battle, the protagonist carries out a certain plan. The Apemen were intelligent life forms originally brought from another planet, at the protagonist's own suggestion, to serve as computing resources to run the virtual reality. The protagonist returns those Apemen to their home planet. The narrator describes this as an act to take responsibility for his own deeds.

The ninth Sol is Eigong. She is the master who taught the protagonist swordsmanship and other skills, and at the same time the researcher who ended up creating the virus.

The narrator calls this final boss fight one of the most fun battles in the game, with a great many chances to land deflections. They also say it's a plus that it lasts through a third form, so you can enjoy it for a long time. In the first form you learn the basic attack patterns, which then evolve with each form change. A distinctive feature is that red attacks have two variants, so you need to read whether an explosion or a grab is coming and respond appropriately.

In the second form, there's first a stretch where you can land consecutive Unbounded Counters, followed by an opening for attacks at the end, so you can replenish a large number of arrows. Firing lots of arrows is key to building damage, and to that end you actively attach talismans. From the second form, the enemy's talisman attack pattern also changes, with follow-up attacks on the talismans. The narrator says they feel this educational design, progressing from basics to applications, expresses the master-disciple relationship between the two. They also say that the game portrays the protagonist's relationships with those around him — master and disciple, siblings, friends, lord and retainer — exceptionally well, and that these relationships drive the story effectively.

In the final form, high-speed lightning strikes that fly freely across the center of the screen are added, making the battle screen very busy. However, the narrator says the rest of her moves are the same as before, so you just need to deal with them calmly and without fear. From here on, the commentary stops and the fight proceeds in silence, ending with Eigong's defeat.

The ending plays without commentary. Afterward, the narrator wraps up by saying that the Solarians' grand plan has come to an end here.

Sharing their impressions, the narrator recalls that the combat design was excellent, and that at first they thought it was a game focused primarily on that aspect. In reality, however, they were surprised right up to the end by the grand Eastern sci-fi world that unfolds, with its space civilization, cryogenic sleep, large-scale computation, and more. They praise the multifaceted portrayal of the Solarians' human drama as wonderful, and call it a game so enjoyable that it was sad to see it end. Finally, they note that the video could only show a small portion of the game's scenes, and encourage anyone who became interested to play it for themselves.