How can I write heroes with powers that have never been done before?

Whatever you can think of in terms of abilities, someone’s thought of it before.

Just one of those things. At any given point, there’s more than a million people trying to write stories with some form of superheroes. This has been going on for 75 years by now. The odds are simply overwhelming that it’s been thought of before.

What you can make interesting are the limitations. Superman, pretty much the original superhero, got very boring after a while, so they gave him limitations: kryptonite, light from a red sun, even magic. The Green Lantern is powerless against anything yellow.

You can play around with that endlessly. Maybe your hero only has powers after improbable preparations, and they disappear against something common. Yitzhak ish Palda, who needs to wear his kippah and is powerless on Saturdays, and only finds out at the crucial moment that he is also powerless against a pork chop. (That sounds like something Mel Brooks would cook up. Maybe he did? Have I seen it in a movie and forgotten?) (Anyway, I wouldn’t try that specific one unless you’re Jewish. Too easy to make a mistake and make absolutely everyone angry. But you get the general idea.)