Destiny - Shura Ball

The seven ghost kings in the other world selected 21 Shura-level devils to come to the world, make contracts with humans, and start fighting each other. The fates of humans and demons are intertwined, and the ghost king of the camp that wins humans' final victory will grant any of their wishes. Dance and please the One on the Throne with your blood and life. (This book refers to some rules and settings of animations such as Fate and Shana, and strives to make every character in the book shine)