I was delighted to discover, while reading Sean Howe's Marvel Comics: The Untold Story, that there was a minor Marvel supervillain in the '70s called Viper, who came from the world of advertising.This bitter and twisted Madison Avenue malefactor was invented by maverick writer Steve Gerber, the creator of Howard the Duck, and first appeared in Captain America #157. His origin sounds like just the kind of circumstance to provoke a psychopathic vendetta against humanity.

"For years," shouted The Viper, "I labored in anonymity selling other men's products, making other
men's fortunes, laying waste to values and the environment of a nation
from the privacy of my office… now I've left that grey flannel world behind!" (Indeed, he swapped grey flannel for green lycra, as you can see above.)

Physically, Viper was a good hand-to-hand combatant,
quite agile, and possessed the normal strength of a man his age, weight,
and height who engaged in intensive regular exercise. Mentally,
Viper's intellect was calculating and without mercy. Besides
advertising, Viper also had some skill in chemistry, allowing him to
create his venom. 

It was lucky that he had chemical / poison skills on the side because presumably on its own the ability to craft a pithy headline or kern some type would be a power insufficient to enslave the free world.

As well as crying "Vengeance!" the Viper was prone to delivering such lines as, "We have a saying in the advertising game, Captain
America! You might do well to remember it: Never turn your back on the
competition!" Wise words, though rival agencies don't usually stab you in the back with venomous darts. At least, not literally.

In their
secret hideout (below) The Viper and his evil allies plot against
Captain America. Viper decides to call an old friend on Madison Avenue and have him devise an ad campaign for "the un-selling
of Captain America". The objective of the campaign is to convince the public that
Captain America is a glory-grabbing vigilante, despoiling the name of
America. The Eel describes this as a nutty idea. (Big talk for a guy whose superpower is the ability to spawn in the Sargasso Sea.) But Viper admonishes him, "Wait and see. Never
underestimate the power of advertising. For the majority of the public all they know is what they read in the papers or see on television! I've hawked absolutely worthless products wth tremendous success." Proving Viper's point about the influence of the press, Eel interrupts, having read
in the paper that Captain America is now in Virginia visiting his
girlfriend. So the three of them decide to "shove the grey flannel tricks" and achieve superior ROI by simply killing Captain America to death the old-fashioned way.

Viper and his gang fail either to kill Cap, or to get their ad campaign off the ground. In the end, Viper is killed by Madame Hydra who tells him that now she will take the
name Viper for herself. Viper replies, "Uh…won't that cause confusion
in the marketplace? I mean I'm the Viper too…" But his "glib capitalist tongue" (presumably forked) can't persuade Madame Hydra. She tells him to shut up and establishes brand leadership in the serpentine category by eliminating the competition.

Great stuff. This suggests an interesting plot direction that could spice up the next season of Mad Men: Don Draper (no stranger to secret identities) is bitten by a radioactive newt and becomes Newtman, able to do whatever a semi-aquatic amphibian can…