Complex sentence: Though defeated, Zera swore that she would be back and she would never stop trying to kill Spawn, who decapitated her and brought her head in front of Goddess Herself, to whom she apologized for her failure.
Split into simpler sentences: Though defeated, Zera swore that she would be back and she would never stop trying to kill Spawn. Spawn decapitated her and brought the head in front of Goddess Herself, to whom she apologized for her failure.