El Hombre

Bravo (left) and El Hombre (right)

El Hombre is an example of a superhero becoming a villain without even knowing it. He is another character from the awesome Astro City comic.
History
Carl Donewicz was the son of  a rich parents. He was fascinated by his uncle's whip techniques and study them. He inherited their own money when they died in a plane crash. Believing the Latinos (which he was among) in his home town needed a role model and wanting to impress Maria Alvarado, he became the superhero El Hombre. Despite originally fighting normal human criminals, he eventually fought villains such as the robot Platinum Blonde, the super fast Getaway and the self-duplicating Los Hermanos. After aiding the Honor Guard, they let him joined. Carl and Maria started to hit it off. Carl began to feel like he was losing his connection to the Latino community. His girlfriend Maria felt in love with the Latino Malcolm X-stand-in Ramon Vega (who is not connected to the real-life individual). Carl adopted an orphan Latino child as his sidekick Bravo. Things in his life started to fall apart when Maria married Vega. He lost his feeling of self-worth when he discover the Honor Guard used his image for merchandise and his merchandise sold the least well. Wanting to improve his rep, he asked the villain Assemblyman to build a robot for him to fight and give him a way to easily stop it. While the Assemblyman made the robot, he made it so the fail safe won't work. As such, the Honor Guard had to stop. Assemblyman, when captured, squealed about El Hombre forcing him to retire. Despite this, Brave continued to be a superhero.
El Hombre is most notable for his role in the "Tarnished Angel" story arch. Steeljack, feeling discouraged about his investigation of the death of minor villains, met Hombre and listened to his life story. Steeljack met up with the new villain Conquistador, a crime lord planning a massive amounts of robberies. Steeljack figured out Conquistador was Hombre. After no one listened him, Steeljack confronted the Conquistador. The Conquistador revealed he is El Hombre. He explained his plan to Steeljack: after getting several villains to commit crimes, he have them met together only to find "El Guerrero" (Carl's new identity) and be murdered by the "hero". Steeljack damaged the armor and caused it to short-circuit thus knocking Carl out. According to Bravo, Carl was thrown into an asylum "for the rest of his life".
Power and Abilities
El Hombre had no power or equipment that gave him superpowers. He seemed to very agile. He used a whip as his weapon of choice.
As Conquistador, he used a suit of high tech armor. While not stated outright, he seemed to have enchanced strength and durability when wearing it. The suit's armor distorted his voice (shown by unusual word balloons). According to Steeljack, he has an oxygen supply in his suit.
References:
Astro City "Tarnished Angel" TPB