The Most Powerful Demon Moons in Demon Slayer are ranked based on their strength, abilities, and their role within the Twelve Kizuki.
Rui
Rui was the first official member of Muzan's Twelve Kizuki to appear in Demon Slayer, during the Mount Natagumo arc.
Rokuro
Despite their considerable strength, Rokuro, Wakuraba, and Mukago were mere pawns compared to their nearly omnipotent creator, Muzan.
Wakuraba
Lower Rank 3 Wakuraba was the first to be killed by Muzan, followed closely by Lower Rank 2 Rokuro and then Lower Rank 4 Mukago.
Kaigaku
Although not as powerful as the other Upper Rank demons, Kaigaku was still a formidable force. He was once Zenitsu's classmate, having trained alongside him under Jigoro Kuwajima.
Gyutaro & Daki
Gyutaro and Daki, sharing the lowest tier of the Upper Moon ranking, lived as one after their transformation into demons.
Nakime
After Hantengu's defeat, Nakime was promoted to the Upper Moon 4 position. Using her biwa, she can rearrange the Infinity Castle and teleport herself instantly .
Kokushibo
Kokushibo was once a demon slayer during the Sengoku Era. He became a demon to surpass his natural lifespan after activating his Flame Mark.