The setting is modern day though this being a superhero story feel free to use time travel if you want to be an “uber high tech guy from the future” or some bloke from the World War 2. Superheroes are relatively new to the world, until now most of those that rely on powers have been quite low power levels. What most people don’t realise is that quite a few of those on the lower end of the power scale are being recruited by some Clandestine agency and being trained as operatives and are unknown to the general public and the lower echelons of Government/military.
One of the most obvious exceptions is Mighty Man who appeared a few months after the other Powers. Mighty Man seems to be of a much higher capability than anyone else on the planet, luckily he’s on the side of good. The population is quite acceptable to Powers as right now the few of them there are defend them against the one or two crazy ones that exist and fight criminals. However, foreign Governments are less happy, so no crossing borders for super heroics. If you do that Government is likely to send someone to intercept you or start criminal proceedings trying to get you extradited from your home country. Mighty Man has managed to get away with that but he’s not really associated with any one country.
Magic is a relatively lost art, there are people in remote locations who still practice rituals and ways that the rest of the world lost centuries ago. As far as the main populace are concerned Aliens don’t exist, however a few Governments around the world know this not to be true and are looking out for aliens who are taking advantage of the rising number of powered individuals to sneak onto the planet and pass themselves off as another ‘costume’ or worse. As far as the agencies whose job it is to investigate Aliens know there aren’t many species out there and not all of them are friendly to humanity. Though that is quite understandable because not all of the agencies are friendly to aliens.
You guys are going to be the newest heroes to arrive and are slightly weaker than the few high powered characters that do exist.