Asura was one of Death's Eight Powerful Warriors/Eight Gaurdians over eight hundred years ago. Partnered with the misterious weapon Vajra, Asura was terrified of anything and not only consumed his weapon, but became a Kishin as to conqure his fears using power. However he was defeated by Death and sealed in a bag od his own skin. For eight hundred years Asura resided in the bag, starved of blood until Medusa and her team revived him using Black Blood.
On the surface, Asura comes off as arrogant and deeply sardonic, unaffected and unatached to anything. He presents himself as a philosophical mind and tries to manipulate others to his way of thinking. However, deep under the surface, Asura is a coward and thus lies the truth of his madness. Fear being Asura's greatest motivation and greatest weakness. When confused or bewlidered, Asura will attack at random, without care of who or what he hits. He simply attacks to get away from what he does not understand, and by exstension, what he fears.
Eight hundred years ago, Asura became Death's most powerful fighter, armed with the weapon Vajra. However, he was the most frightened of Death's fighters, wrapping his head and face in scarves and layering five shirts, one on top of the other. Because of his fear, Asura became obssessed with power, and became driven to collect the souls of humans. However in order to do so, he had to first swallow his weapon Vajra. Once that was complete, not only was Asura able to consume Kishin Souls, but was also able to cough Vajra up to blast bolts of red energy from his mouth. After Asura became a Kishin, he was wrapped in a bag made of his own skin and was drained of bloor. In his prison he waited for eighthundred years before his release.