So I have a real challenge for the mecha manga/anime buffs around here. Here goes:
Way back in the mid 1990s, I borrowed a VHS tape from a schoolmate that was some kind of mecha anime. The only things I really remember about it are that it featured a robot character called "The Colonel", who said something along the lines of "your world has become entangled in our problems", that there was a human character called Karachi, and that it involved a subplot of a man who pretended to be mentally enfeebled in order to keep some sort of aristocratic woman from assassinating him. He later got rid of her and assumed power, and controlled a giant floating mecha without legs (a giant flying robot torso with arms basically) called "Libo" or something similar. One other scene I distinctly remember was that this aforementioned aristocratic woman went insane, was holding her dead infant son in her arms, convinced herself that the boy was still alive, and asked her terrified handmaidens to go get him something to drink.
This isn't much to go on, but if any of the above rings a bell, please let me know. I've been browsing mecha anime lists like crazy, but haven't been able to find anything so far.