Black Adam
What do you think about the anti-hero known as 'Black Adam'?
Black Adam is a Fawcett Comics and DC Comics supervillain, often a rival of Captain Marvel. He wears a similar costume to Captain Marvel, but the red portions are colored black and Adam does not wear a cape. Created by Otto Binder and C.C. Beck as a one-shot villain for The Marvel Family #1 in 1945, Black Adam was revived in the 1970s Shazam! series as Captain Marvel's most powerful foe in terms of physical abilities.
Ref. Answers.com
Black Adam has been both good and evil through out the years both fighting the JLA and being part of them. The problem lies in the fact that Black Adam is both the ancient Thet Adam and the evil spirit of Theo Adam. Theo is suppressed but finds ways to get loose and cause evil and destruction. His power base is similar to Captain Marvel, but he no longer needs magic words to summon his power. He derives his power from a magical scarab which contains the power of the gods of egypt. He has a very long and complex history, you can read all of it here.
https://www.mykey3000.com/cosmicteams/profiles/blackadam.html