To the OP - Was this request inspired by Aldnoah.Zero?
The Legend of the Galactic Heroes comes somewhat close to what you're looking for.
I 2nd Obelisk ze Tormentor's
Arpeggio recommendation. That fits your requests rather well.
I honestly can't think of anything else off the top of my head. "Normal human who stays completely normal vs. Overpowered enemies" is honestly something that is rather rare in anime/manga, to the best of my knowledge. Few Batman-types in that regard, and what ones there are tend to have "powers" of some sort (such as fancy mechas).