One's an intentional thing. Though the superheroes don't know who's handing them out, they know it's being handed out. Producing all sorts of reactions from paranoia to ecstatic religious trust. (My somewhat slothful heroine points out that people shouldn't get dependent on her.) Mind you, the people who are given it show that either it's multiple agendas, or the source is handing them out to a large variety of people. (Witness you get both heroes and villains.
The other one is more random and wacky and involves Mad Science and a Victorian circus. (Would be one reason in universe to have their costumes based on circus ones. 0:) Noticing it opens the door to a lot more random plots. A world in which a lot more people with powers take to other occupations, perhaps. A lot more caprice and misfortune in picking up powers.
Contemplating them quickly sorts out most superhero story ideas I've got into one or the other.
The first one, of course, requires that I decide when the superheroes started. The second one -- I was thinking that obviously it would start out steampunky, with the rise of science producing the rise of mad science. but does it need to? Could there have been alchemic or such like supers? hmmm. . . .