Champions

https://www.herogames.com/hero_system_basics.html/

I used to play some previous editions. It's extremely flexible. It's a point buy system. It has, for example, ways of defining a power that requires something external (which makes it cheaper in points), e.g. flight using a jet pack, and if that thing can be taken away. So you could build a Spider-Man that has web shooters that require ammo or you can make the one that spurts ropes right from his wrists.

It's also flexible in that there are two types of damage. The first is more for a more brawly combat where you get them down to 0 stamina (or whatever it's called) and they're unconscious. Then there's killing attacks that go for hp with an eye for making the other character dead. This makes it very easy for codes of conduct (e.g. no killing, which is also done with points) to easily be defined mechanically. Attacks can also be defined by what they can get through, like a psychic attack won't be dampened by physical defense (but might have a weakness against unobtainium).

There's also ways to build plot into characters. You can buy things like people important to your character ( that you may have to rescue), sidekicks, information contacts, nemesis, superior officers, organizations, etc.

My group managed to make great knock offs of Superman, the Flash, Iron Man, etc., but also had no problem with making a Sentai squad or a character that could copy abilities by absorbing them (which I suppose both MegaMan and Rogue do, but in different ways which you could define with this system).

And depending upon how many points you play with can determine if you're doing Daredevil keeping the streets clean type things or Avengers save the multiverses type thing.