Go! Go! Ackman

A demon child who is 200 years old named Ackman awakens after sleeping for fifty years. His parents inform him of their task to murder individuals and trade their souls to the Dark Lord for financial gain. Following a clothing upgrade and a sword from his sister Medusa, Ackman starts carrying out these killings. A red bat-winged creature named Goldon collects the souls in a jar as Ackman commits these acts.