The entire Freedom Phalanx is Derivative. Some more than others
Manticore is a take on the Green Arrow, in the batman sense that Green Arrow originally was intended.
Statesman is derived from Superman with a dash of Captain America.
Synapse is some kind of derivative of the Flash.
Back Alley Brawler is a take on Luke Cage.
Etc etc.
So just follow those examples.
Yeah.
If you want to use an established character for inspiration, just make sure its changed enough that its a derivitive character instead of a copy.
Moon Knight was originally a derivative of Batman.
Rohrscarch was a derivative of The Question. The Question was a derivative of The Shadow.
How much of your own spin you add, the less people will think its a copy and more will think its a worthwhile character in its own right.
Almost every idea has been done before.
Superman, batman and the hulk aren't completely original either.
The hulk probably the least so, he is straight up the "atomic" version of Mister Hyde.
This idea is dumb.
Its really very simple, just imagine you are starting your own comic book company.
What are your limitations?
Can you make Superman Comics? Of course not.
Can you make a comic about the last survivor of an Alien race who has super strength and can fly? Sure. As long as you change enough story details to blur the lines?
Can your character look like Superman in a Superman costume? Nope. Can he be a tall muscular handsome guy with dark hair and blue eyes? Sure.
Would this comic be called unoriginal? Possibly. Probably if you stick too close to the Superman formula.
I ran my Stalker through a completion run and ran through all the arcs, etc. STJ/EA went good. But I've given this some thought.
I think a (Favorite Primary)/Ninja Scrapper would be a good choice for something like this. You get a self heal, Endurance heal, In set Stealth, with lots and lots of movement from a low level.
To do this you would need raid bosses that dropped purples so people had a reasonable chance of getting one for x amount of effort.
Doesn't sound like COH
If you focus on one Character you can easily afford to be "All Purpled Out" and have Hundreds of Millions in Influence only playing a few hours every week.
With no marketing. Just doing Solo Story Arcs and Task Forces.
That character is just as good as one of some extreme farmer/marketers 50 "All Purpled" out characters.