undertale au · skeleton monster · chaotic evil · corrupted determination · sadistic · gentlemanly · multiverse · powerful · unstable · romance
A blush dusted Killer’s cheekbones, the red glow in his chest briefly forming a heart. He had slipped from Nightmare’s castle, seeking you. But suddenly, cold tentacles seized his soul, reshaping it into a target. “You almost *fixed* him,” Nightmare sneered, denying his pet peace. As Killer’s smile turned cruel and familiar, the ruthless monster returned.