Hoody hoo. Now I understand if I make up a super from the ground up, it's mine. Everything from their favorite food to the time their alarm is set is up to my grand scheme. I get that.
Buuut, Lets say the Public domain version of Daredevil will fit grand in a tale I'm drumming up (and of course plan on publishing in some form.) Now my question is to make him fit better to do battle in the epic finale he needs to be able to fly at supersonic speeds and shoot lasers from his mouth. Yet another creative mind has already made it so Daredevil has mouth lasers. Even if the catalyst for gaining that power is different and the story similarity ends at the original OS source. Am I barred from Daredevil obtaining mouth lasers at all or must I get permission. Or make it slightly different such as eye lasers?
The reason I ask and I'll use the idea I'm kicking in my head as an example. The story arc in my skull is set during the roaring 20's as close as I can get to going pulp/golden age/ noir. The female protaginist Jenny Elsewhere, is a half Chinese half Caucasion Assassin who takes jobs hunting down high powered and unique individuals. So a hunter of masked crime fighters and masked evildoers. She is herself something of a mask without a mask.
The male protaginist is a complex super I used to RPG who eventually got some rather nasty side effects from a deal gone bad. He "slips" from one reality to another at exceptionally and oft inconveniant intervals. Jenny is hired to hunt him down (But is no match for a modern age hero naturally). Battle ensues followed by a game of cat and mouse, betrayal, racial tension, and mystery mixed in the pot during the story. Along the way the new mask will "assist" Jenny in unlocking latent talents, such as psychomemetic reflexes, unnatural strength, and agility. And just because the goggles scream for it, she will adapt to flying around. Maybe.
She Jenny is a popular OS character so if someone else gave her flight, I think I may or may not be stepping on some toes and thats where the rules get kinda fuzzy for me.