A tool. That is all he is to them. They changed him, improved him, while taking what makes him human.
Just a long cycle of tests and experiments. Now, they need him for an important test. Teleportation. For better or worse, he ends up a bit farther than expected, like a lot farther. Now, he needs to learn to coexist with this bizarre world. However, those that sent him away aren't very willing to let him go...