As one can see, Dr. Chaos is the opposite of Dr. Fate. His costume is identical to that of Dr. Fate's but the colors are reversed, and instead of the helm housing a Lord of Order, it is instead the home of a Lord of Chaos. The helm was found by Burt Belker, in the Ur Valley of Earth 1 (Dr. Fate's home is in the parallel world, Earth 2). When Burt donned the Helm he became an agent of Chaos.
Surprisingly, Dr. Chaos is not an enemy of Dr. Fate, but instead appeared in the pages of, and was defeated by, Superboy. I believe Dr. Chaos was a one-shot villain as I don't think he ever appeared again after his defeat by Superboy.