Helck manga volume 4 features story and art by Nanaki Nanao.

Crossing a ruined wasteland, Helck and Vermilio are attacked by the Warrior of Darkness! Helck displays his true heroic power as he clashes with the strongest foe he’s faced yet. But Helck’s overwhelming strength causes Vermilio to doubt him once again, so he reveals his past - and the reason he wants to destroy all humans.