Asura is the main antagonist of Soul Eater. He was a member of the Eight Great Warriors also known as the Great Old Ones. Asura was Shinigami's first son.
Asura was a member of Lord Death's personal Squad, but began breaking a rule by collecting human souls and his own weapon. So Lord Death imprisoned Asura in his own skin to stop his killing spree on human beings.
With the help of Medusa, Asura escaped his prison. He then encountered Lord Death and fought him in battle. Afterwards, he retreated from battle.