Doctor Apocalypse is an extremely powerful supervillain famous for his attempt to violently take over the East Coast of the United States in the early 90’s. The Doctor has access to extremely high level technology (has demonstrated the ability to generate super-storms and attacked NYC with a massive modular robot) as well as access to a wide range of powers from another dimension. He did not participate (to the best of your knowledge) in repelling the Pirate invasion.
His son, Benjamin Apacolos, is currently in the New Jersey State Penitentiary for the deaths of 14 women under the guise of ‘The Chesapeake Strangler’
He has appeared as a form of ‘mass-hallucination’ to the citizens of Oakland, San Francisco, Pacifico, and Monterrey. He has demanded the surrender of California to him as an independant nation. As an example of his power, he created an earthquake in the city of Monterrey (accidentally releasing the Monterrangutan).
Following an interview with Benjamin, it has been learned that the Doctor gets his powers from the jewel embedded in his forehead. The jewel provides a dimensional connection to a demon-infested world. Using the jewel, the Doctor can wrest any power from the demons in that world.
The Doctor was captured following a titanic battle with the Eclipse and the Paragon Society. He was taken into MEDUSA custody pending transfer to a more secure facility. Unfortunately the Neural Dampener that was deployed disrupted the Doctor’s willpower and allowed demons to enter into the world.
Apocalypse was freed from MEDUSA custody by members of the California Republic