Since I'm currently building a Doctor Who spinoff over thataway, it's got me thinking about DIYing settings, as for example Steve D's Campaign Toybox.
So I reckon I'll post some settings here.
To start with, a bit of recycling, from here, and previously from some games I've Actually Played (the Tyranny never arrived in-game, though):
A Classic Superhero Setting
Future, the Archetypal First Hero, could fly, was really strong, wore a cape, fought in World War Two, and was loved by all for his altruism and caring. And unless someone wants to play him, he died saving the world a few years ago or went missing while going out to stop a rogue asteroid that was going to destroy the planet.
The Darkness, the Archetypal Sinister Vigilante, is an urban legend, punching out Dick Tracy style villains and leaving them tied up for the police in Deprived City With Gargoyles.
Sergeant Power, the Archetypal Patriotic Supersoldier, was supposed to be the first in a production line, but something went wrong and he became a single, remarkable player in the theatre of war.
But unless someone wants to play them, they're all off-stage. It's time for the PCs to become the stars of this setting.
Just to be different from the Big Two, Atlantis is full of people who aren't particularly good swimmers, but they build great submarines. And it's ruled by a Senate, rather than having a brooding Prince who talks to fish.
Lyonesse also reappears, full of Arthurian knights. The Time of Endings has arrived, and the Once and Future King will ride out to save the world again. If someone wants to play him, this is important, otherwise it'll be a crossover event next summer that the PCs play a surprisingly major part in.
(A couple of these subsections could be pulled out and made into related-genre settings of their own.)
SABER - Senate Advisory Bureau on Extranormal Research - has been around since Archetypal First Hero appeared, formed by the agents who'd dealt with Pre-Comics Pulp Daredevils and Mystery Men. Agent G-5, who first battled The Secret Of The Orient in the late 1920s, is still in charge despite being over a hundred years old and he doesn't look a day over forty-five. If one of the PCs is a SABER agent, they'll be important, otherwise they're there for occasional crossovers and to drag away international villains after the PCs whomp on them. Optionally, they could provide a supers liaison, who bears a passing resemblance to a popular superspy character of whichever decade we're talking about such as Mrs. Peel or latterly Sydney Bristow.
Overlord was once a man. A brilliant physicist, engineer and alchemist, he had seen too many wars fought for twisted or perverted ideals, and sought to conquer the world for its own good, the ultimate meritocracy. He fought Future, SABER and The Science Five repeatedly over the years, striking from his floating base "Overwatch", until he died in a battle with the Five and (the predecessor or parent of a legacy hero), when they failed to save him from the deathtrap he meant for them as Overwatch's thermic reactor exploded. And then, six years later, rumours began to spread that Overlord still lived, risen from the dead and seeking revenge on his enemies and all the world. Some say that his baroque battle armour is empty, driven by the alchemist's ghost or the machinery he created...
On a much smaller scale, Edgar Drake is the untouchable head of Deprived City With Gargoyles' most powerful crime syndicate - and two of its main competitors. He keeps any potential threats to his reign in check by having them fight each other. He presumes that eventually Darwinism will lead to one winning, and on that day he will be glad to relinquish his power to the stronger man. In the meantime, he is a charming and affable society host, a trustworthy business partner, and willing to snap your neck without blinking should you threaten to expose his secret or endanger the life of his daughter, DCWG University star student Celia Drake. Protecting her from the harsh realities of his life is his highest priority, having sworn it to his wife on her deathbed.
Drake's foremost rival is The Snake, the yellow-eyed, double-jointed, fork-tongued maniac believed to have started his life in a travelling show before killing the abusive ringmaster and escaping at the age of ten. Pathologically incapable of empathy, the Snake is a master thief and a literally cold-blooded killer, who could have retired years ago but finds his only pleasure in the intellectual challenges of crime.
Meanwhile, in the depths of space, the armies of the Tyranny assemble to ravage and conquer another world. Dozens of species work as slaves in the depths of their black and purple starships, powered by chained black holes, and the scientific minds and strong backs of humanity will be a valuable prize to the Tyrant and his council of backstabbing advisors. Opposing them is a rag-tag fleet of escapees, other strange alien beings, and long-lost travellers from Earth. If you're playing them, this is important right away. If not, it'll crop up when the Tyranny fleet reaches our solar system and SABER nudge the PCs into a spaceship to investigate. And at some point, the PC strong guy will end up in a gladiatorial arena fight with the Tyranny champion and/or a captured rebel hero.
Also, consider some more stock elements.