I had a version like this as well.
Superman - last survivor of Krypton. Ferrying an infant across space is not feasible for Jor-El, so he instead sends a machine that will grow a perfect specimen of the dominant life-form on that planet, and since it lands on Earth, that's human. (Kryptonians weren't even humanOID!) The transport also downloads the sum of Kryptonian lore into the developing baby human, and has the ability to recreate Kryptonian arms and armor, gene-coded to only work for someone with his unique Kryptonian markers in his genes. He's basically an alien Iron Man (armored hero) / Captain America (perfect physique), but doesn't have any actual super-powers, just a Kryptonian 'Creation Engine' able to spit out nano-factured Kryptonian machines and weapons. (More of a Batman niche, powers-wise. Great physical traits, awesome gear.)
Batman - empowered by the Mesoamerican god of bats and the night, Camozotz, this grim man has supernatural powers of transformation, into a flock of bats, a giant bat, or a man-bat hybrid, with great strength, senses and speed, particularly at night, as well as control over / communication with mundane bats. He can also communicate with Superman at a frequency his alien armor can overhear, but regular humans cannot (which is very upsetting to dogs, apparently), making for some subtle and impressive teamwork between the Brave & the Bold. (More of a Wonder Woman niche, empowered by gods from ancient mythology.)
Wonder Woman - a sorceress with seven signature spells, based on the colors of the rainbow (which she never calls her 'Seven Wonders' for legal reasons...). Defensive, offensive, transport, utility, healing, she does it all, but only one big spell at a time, since they are maintained by her will and focus! Her powers have nothing to do with the Olympian gods, but a form of psycho-spiritualism, and she is a counselor by nature, not a warrior, although she's earned the respect of the others because of the power and versatility of her magic. (Totally different niche, since Diana was already a lot like Kal, strong, fast, tough, flight, etc. I wanted to break her out into a new direction and give her more think-y abilities and less tank-y ones.)