The 12 Upper Moons are a group of powerful demons in the popular Japanese manga and anime series, Demon Slayer: Kimetsu no Yaiba. They are the top-ranking members of the demon clan, each possessing immense strength and unique abilities that make them formidable opponents for the series’ protagonists, the Demon Slayer Corps.

Here are the names and abilities of the 12 Upper Moons in Demon Slayer:
- Kokushibo, the Upper Moon One: Kokushibo is the strongest of the Upper Moons and the twin brother of the series’ main antagonist, Muzan Kibutsuji. He is a master swordsman who wields a demonic sword called Kyokotsu, which can extend and retract at will.
- Doma, the Upper Moon Two: Doma is a sadistic demon who enjoys playing with his victims before killing them. He has the ability to control people’s emotions and can make them feel intense pleasure or pain.
- Akaza, the Upper Moon Three: Akaza is a former human who was turned into a demon by Muzan. He is a skilled martial artist and can regenerate his limbs almost instantly.
- Nakime, the Upper Moon Four: Nakime is a demon with the ability to create illusions. She can manipulate the perceptions of those around her, making them see things that are not actually there.
- Hantengu, the Upper Moon Five: Hantengu is a shape-shifting demon who can split into multiple bodies. Each of his bodies has a different personality and ability.
- Gyokko, the Upper Moon Six: Gyokko is a demon who can control insects. He uses them to spy on his enemies and can also command them to attack.
- Daki, the Upper Moon Six: Daki is a demon who can control threads of spider silk. She uses them to entangle her enemies and can also use them to fly.
- Gyutaro, the Upper Moon Six: Gyutaro is the twin brother of Daki and also has the ability to control spider silk. He is a skilled swordsman and uses his threads to enhance his attacks.
- Nakime, the Upper Moon Six: Nakime is a demon with the ability to create illusions. She can manipulate the perceptions of those around her, making them see things that are not actually there.
- Gyuutaro, the Upper Moon Six: Gyuutaro is the twin brother of Daki and also has the ability to control spider silk. He is a skilled swordsman and uses his threads to enhance his attacks.
- Kokushibo, the Upper Moon Six: Kokushibo is a master swordsman who wields a demonic sword called Kyokotsu, which can extend and retract at will.
- Akaza, the Upper Moon Six: Akaza is a former human who was turned into a demon by Muzan. He is a skilled martial artist and can regenerate his limbs almost instantly.
It is worth noting that the Upper Moons are not all equal in strength, with Kokushibo being the strongest and some of the lower-ranked members being less powerful than others. Additionally, some of the Upper Moons have been defeated or killed throughout the course of the series, while others are still active antagonists.
In conclusion, the 12 Upper Moons are a group of powerful demons in Demon Slayer: Kimetsu no Yaiba, each possessing unique abilities and strengths that make them formidable opponents for the series’ protagonists. While they are not all equal in strength, they collectively represent some of the most dangerous and powerful beings in the series.