Marston's "Wonder Woman" is an early example of bondage themes that were entering popular culture in the 1930s. Physical and mental submission appears again and again throughout Marston's comics work, with Wonder Woman and her criminal opponents frequently being tied up (or otherwise restrained), and her Amazonian sisters engaging in frequent wrestling and bondage play. These elements were softened by later writers of the series, who dropped such characters as the Nazi-like blond female slaver Eviless completely, despite her having formed the original Villainy Inc. of Wonder Woman's enemies (in "Wonder Woman" #28, the last by Marston.)