On Earth-S an agent of the North Koreans during their war with America, the Great Red Brain, filled the same niche of brainy bad-guys as had his Earth-One doppleganger of the Brain and Earth-Two counterpart of Mister Mind.
While there was never an origin for this entity, it was created by the villainous scientist known as Tong to give his nation a superior resource over other countries around the world. The Great Red Brain had tremendous mental might and technology which taxed the combined abilities of the Marvel Family, although his exploits would be vastly more limited then his synthetic cosmic twins two universes away as he would be destroyed seemingly forever after the Family combined their might to overpower its vast capabilities.
And then there was humanoid Mister Wonderful and synthetic man Invincible Man whom the alien insect from Earth-Two's universe Mister Mind occupied as various times between his tours of duty as mastermind behind the Monster Society of Evil. Mind on Earth-S would be reborn after his former form had perished following his being electrocuted, with Wonderful's dopplegangers on Earths One and Two being the disembodied French scientist known as the Brain and the diminutive inventor and former Mind recruit of the Dummy. Invincible Man's cosmic twins on those worlds being the advanced ape known as Monsieur Mallah and the original Mister Mind himself while in control of the monster Oom's bestial body.