Disembodied Brains and Monsterous Henchmen and Masquerading Madames

Mysterious madmen maneuver malevolent minions methodically. Well, the men in question are the mysterious Brain with his arch ape Monsieur Mallah and their shape-shifting ally Madame Rogue from Earth-One, as well as their counterparts the insane Jason Rogers who possessed a disembodied brain attached to the bestial body of the Monster.

These scheming terrifying triads came to the attention of the Doom Patrol as well as the All-Star Squadron. But what was the secret behind these villains?

Turns out the Brain was a former French scientist whose body perished but his brain was preserved thanks to the timely operation of Mallah, a mentally augmented gorilla that had served him for years prior to the death of his body, and formed Earth-One's Brotherhood of Evil to do his bidding.  While the counterpart as this evil organization was Mister Mind's Monster Society of Evil on Earth-Two, As for the Monster and his twin brother Jason, the pair each took turns controlling his body, with Jason being the dominant persona until evil impulses caused the mind of his twin who had never developed an individual body asserted control, transforming Roger's form into the Monster that like Mallah had both massive strength and seemingly inhuman features.

While the Brain recruited various criminals to form his Brotherhood of Evil, all freaks like himself and his ape assistant, Mister Mind sought out various adversaries of the Justice Society. French actress Laura DeMille was brainwashed and then operated on by the Brain into becoming the Madame Rogue. Shortly therafter, the Brain gave DeMille the ability to alter her features as well as elasticize her body. 

DeMille would ultimately aid the Doom Patrol as she fell in love with its leader Niles Caulder, then betray both the Patrol and the Brotherhood. After Niles and the Patrols death, she attempted to conquer an African country and finally met permanent defeat when she perished while battling the New Teen Titans, Robotman and a new Brotherhood.

DeVille's counterpart on Earth-Two was the shape shifting scientist known only as Mister Who. Who was a recurring foe of Doctor Fate, and later opposed the All-Star Squadron as a member of the Monster Society.

Eventually both the Brotherhood and Society fragmented with the Brain and Mallah forming a new incarnation of their team with four powerful pawns, while the Monster was later employed by Per Degaton into a new assemblage of time tossed tyrants in the early 1940's who battled the All-Star Squadron during their initial formation.