Description:

Kakugo and Harara are two siblings who have been trained to fight demons, monsters, and other creatures that are now roaming about in the post-apocalyptic 21st century. Along with their superior fighting techniques and specialized skills, they were also given special suits called Zero armor, which were made from the souls of dead warriors. Unfortunately Harara succumbs to evil within the Zero armor, and Kakugo is the only human alive that has the skills and equipment to defeat his sibling.

Description:

In this world, there exists individuals known as "Majin"—supernatural beings able to wield unique powers. They live among the normal human beings, but the rift created between the Majin and the normal human race is severe. There exists a school known as Dangerous, where the population ratio of Majin students exceeds that of any other high school. In this school, two groups known as the "Banchou Group" and the "Seitokai" face each other in war, but they have created a balance of power, resulting in a temporary peace. Now, with the inclusion of new students, this balance of power is about to collapse. One of the "normal" students, Ryouseiin Otome is forced to choose sides before the beginning of Armageddon. (Source: MangaHelpers)