Armin is pre-Moebius, and Min Cho was his infiltrator self - an orphan from Joseon, raised by his sister after a house fire when he was 10, who is a genius and scientific child-prodigy. Getting into University at the age of 12, he was recruited by the evil secret organization Vexiator, who saw both his talent and that he and his sister were vulnerable enough to take advantage of. The brainwashing was not as effective as the other scientists assumed it would be, and the Mantis broke out and killed all the scientists, with the exception of the Cho siblings - but they both believed the other to be dead. Min didn't feel his life was worth living anymore, with everything taken from him - but he refused to let everything his sister had sacrificed to make him a scientist be in vain. So he dedicated himself to becoming the best scientist in the world.

Obviously, this included learning from some of the current scientists who vied for such a title, and Blitzkopf understandably topped that list. This is what lead Min to, by whatever means, make it aboard the flight of the Zeitgeist to meet him.