The Justice League of America
Most DCU canon heroes and villains, to which I claim no ownership.
Superman/Kal-El/Clark Kent - The Gentle Giant of the JLA, Superman--Daily Planet reporter Clark Kent by day--will succeed where his colleagues fail; he will befriend the Witchdoctor and ultimately play a large role in reconnecting the mysterious figure with his true-self.
Batman/Bruce Wayne - The World's Finest Detective, technological supergenius, and martial arts master, Batman--billionaire Bruce Wayne by day--does not share Superman's enthusiasm for Doctor Fate's agent, the Witchdoctor. While the masked magician may have gotten past him initially, Batman never gives up an intellectual fight, and he will not rest until he knows, without a shadow of a doubt, that the Witchdoctor--and more importantly, Fate--can be trusted.
Oracle/Barbara Gordon - Formerly Batgirl until she was paralyzed in a fight with the Joker, Oracle is the JLA's face behind the monitor. There is, literally, virtually no way to keep her from finding you.
In minor apperances:
Wonder Woman, Princess Diana of Themyscira
Martian Manhunter, J'onn J'onzz
The Flash, Barry Allen
Green Lantern, Hal Jordan
Aquaman, King Orin of Atlantis/Arthur Curry
The Witchdoctor - There is little truly known about the Witchdoctor. He openly admits, however, that his cause for intrusion on the Justice League's affairs is because he was ordered to--by Fate--in order to gain insight into a spell that might be able to break the wall separating his superhero and civilian consciousnesses. However, he seems to be making more enemies than friends
Doctor Fate/Kent Nelson - One of the original Doctor Fates, the Witchdoctor returned the Helmet of Nabu to the afterlife so that Kent Nelson, arguably the best Fate, would help him break the curse separating the Witchdoctor's personal and superhuman life.
Madame Xanadu - A superhuman fortune teller, Madame Xanadu currently leads the Sentinels of Magic with Zatanna. They keep tabs on most, if not all, magic users of our realm. The Witchdoctor, however, seems to elude their magic at every turn.
Lois Lane - The infamous reporter from the Daily Planet, who is ProHero one article, and equally AntiHero in the next. Lois is daring and bold and has no problem bossing Jimmy Olsen, her photographer, around. She is very close friends with Clark Kent, but is completely unaware that he is Superman.
Avery Byrd - Clark Kent's new roommate. He is a school psychologist and counselor at a high end high school in Metropolis that grew up in England with his parents.