[ Yeah, it's like this place. The enemy is different, but Eren is fighting for the same cause here as he is back home. To win, and live.

His expression grows grim, though, because it's no pleasant explanation. It's for that reason Eren doesn't tend to go out of his way to explain his story.

But he isn't secretive. So— ]

We're trained to fight against Titans. They're giants that'll stop at nothing to hunt down every human they can get their hands on and eat them.