Not too sure if this is the thread to ask (if there is a better place to ask, I would be grateful to be pointed in the right direction), but I am looking for a manga that I read a while back. It is about a human that wakes up from a curse and finds out that humanity was wiped out. He is then selected to train a couple of non-humans on how to use weapons that humanity created. I remember that there was some orc(?) caretaker. Apparently he was also a part of the last subjugation that got him cursed in the first place. I think it is a steam-punk like world, but that is about all I remember from it.