How dreary – to be – Somebody!

The original infinite worlds of the multiverse were ravaged by the destruction wrought by the Anti-Monitor. By the time he was defeated, the only remaining worlds were Earth-One, Earth-Two, Earth-Four, Earth-S, and Earth-X.

Those five remaining Earths -- their histories, their survivors -- were all combined into a single universe.

This was the gestalt Earth, post-Crisis.

This is the world that our Eddie Bloomberg (Kid Devil), originally from Earth-One, ended up in. This is the world that Jason Todd (the version who stole tires off the Batmobile) originated from. And it is not the world known as New Earth. The gestalt Earth existed until Alexander Luthor of Earth-Three attempted to recreate the infinite multiverse, until it was replaced by a new and different Earth with an altered history.

New Earth is part of the Orrery of Worlds, a multiverse consisting of 52 worlds that are each watched over by one of the 52 Monitors who came into existence after the events of "Infinite Crisis". New Earth is the world of origin for the Eddie Bloomberg who would eventually make a deal with Neron for superpowers and be known as Red Devil.

At the end of his first series of adventures, Kid Devil’s parents agreed to leave his education and supervision in the hands of a trio of professors from the Institute of Hyper-Normal Conflict Studies -- Dr. S.W. Kirschtorte, Dr. Irving Bleinseid, and Dr. Elvira Coddleston.

They taught him a lot about mechanical engineering and gadgetry, and also assisted in updating his power armor suit

(to the all-red form as seen in "Young Justice" volume one).

When the device built by Alexander Luthor and Superboy-Prime threatened the stability of the gestalt Earth, the professors and their young protege attempted to understand and counteract the phenomenon. The idea was to create a protective field that would keep their Earth from being changed... however, things happened too quickly for such a large countermeasure. Instead, Dr. Kirshtorte pushed Eddie into the test chamber they were able to build, just as they ran out of time. As New Earth came into existence, an energy wave swept the world... the Institute was wiped from history, and all the people who came together and worked for it were relocated as their histories changed... except for Earth-One's Eddie Bloomberg. He was left alone in a test chamber in an otherwise abandoned building, with his history and memories intact.

Eddie's native language is (American) English. He learned Hebrew as part of his Jewish heritage.
He gained fluency in German and Spanish while living at the IHNCS.
He has limited experience in French, Arabic, and Mandarin Chinese but has a "tourist" level of understanding... he can hold a conversation, especially if he has a translation dictionary in hand.