Lots of superheroes are “children of the atom” in the sense that they derive powers from some sort of radioactivity (think Spiderman or Hulk or even Daredevil) while others are just born with powers without explanation (X-Men, Thor, Superman, Aquaman, Wonder Woman).
Who is a superhero that is somehow grounded in reality, meaning that they could “potentially” make sense (either their origin story is believable, even if it has some obvious gap to make a super power happen, or their power is somehow limited or constructed in a “reasonable” way).
I guess with these restrictions, Batman would be OK since he’s got no superpowers, but he’s insanely rich and therefore can both train himself and have access to sophisticated gadgets, but can you think of less obvious ones (even if they’re minor characters)?
Thanks for reading this!
Edit: thanks for all the answers and apologies for the slow replies. I’ve had a couple of complicated days. I’ll now go through answering you. Several people made me realize I hadn’t been precise in what I meant and helped with their answers. I was looking for superheroes or superpowers that are somehow “believable” in that they’re either constructed in an unexpected way or in a way that you could almost accept as plausible
Green Lantern! Take one Regular Human and add one Alien Ring.
Everyone in Watchmen.
Doctor Strange, just learns magic.
Watchmen is a great answer! All characters are normal people, save for Dr Manhattan and, even if the source itself of his super power is “sketchy” (in that it involves a radioactive event that just makes it true, without real explanation), there is a long section showing us how he tried to reassemble himself very very slowly while learning how to use his new powers which makes for a great and detailed origin story.
Doctor Strange is also a great answer since it taps into something that people have believed existing for centuries (aka magic) and Stephen Strange goes on to study it to save his own hands. It’s a great origin story!
Green Lantern is also awesome in that it’s a very unexpected origin story with aliens from Oa and lanterns being used to give this incredible power. I would say it’s unbelievable as a power (with respect to the restrictions I was thinking about in my post), but the origin story and lore is much more unexpected than so many other superheroes