The stories
Fantomah was a white woman in an African jungle, Stardust an alien. Both fought bug-eyed monsters, mad scientists, and gangsters, but Stardust was obsessed about Communists. Both excelled at avenging atrocities after they happened. Their punishments were god-like, bizarre, and gruesome. Their sole objective was punishing the guilty.
Antagonists were motivated by victimhood, greed, revenge, or power. Mass murder was an acceptable means to greater goals. Even those with sympathetic reasons commit unspeakable crimes.
Atrocities allowed by the gods
Fletcher Hanks disasters rival today's Marvel movies. Entire cities, villages, and populations get destroyed.



The antagonists
Hanks villains have distorted skulls, deep cheekbones, and protruding lower lips.



The art
Fletcher Hanks drew his heroes with all the beauty he could. His drawings of the villains reflect the grotesquerie of their beings. Like the Conan stories by Robert E. Howard, Hanks monsters were based on actual lower life forms. His page layouts and storytelling were primitive even by 1940 standards. Wolverton did similar work with more evolved drafting and wit. Milton Caniff, CC Beck, June Mills, and HG Peter also produced much better work.
The monsters
Fletcher Hanks creatures are overgrown distortions of actual lower life forms.



The SFX
Hanks built his visual language on sheer creativity and tyranny of will.



Problematic creator

In the 2007 Fletcher Hanks collection I Shall Destroy All The Civilized Planets!, Fletcher "Christy" Hanks Jr. said his father was an alcoholic who beat his entire family:
"He kicked me so hard once at the top of the stairs that I landed halfway down. My teachers couldn't understand why I was a nervous wreck! My sister and I hated, hated him. We talked about killing him."
Fletcher "Christy" Hanks Jr. on his father in 2007
Hanks was monstrous as the villains he created. He disappeared in 1941. His frozen corpse was found on a New York City park bench in 1976.

I've grown to appreciate Hanks' eccentric vision. His comics are face value children's stories with no underlying subtext. The self-righteous violence echoes Grimm's Fairy Tales. Hanks only missed their insight, empathy, and humor.
His visual language, however, is uniquely compelling. Comic books and superhero genre were still in their infancy when he worked. Kirby, Ditko, and Crumb are the only ones I can think of that even come close to his level of world-building.
Signal-to-noise
Bangers like the Leopard Women of Venus are worth going through a ton of bad pages.
Dave Marshall, writing from the Fletcherverse
*By preceding Wonder Woman's first appearance, Fantomah is the first super-powered woman in American comic books.