Actually what happens in episode 3 for me wanted to watch more but hated for what they did. Plus when I said the MC whines and does nothing, it gets worse or you actually start noticing it after episode 3.

The Third is just the title and species name Davis. There is no First or Second. I mean technically the species is I think human created (so they aren't aliens) and called cause of their 3rd eye. So Second would be normal humans. Still, it is a good show I totally agree. She even gets a mech later with a large katana as well.