Bad Vacation Idea?? 1 Week During Halloween-Mexico City

I’m up to go anywhere in the world, as long as it’s a kick- ss Halloween vacation! I’ll be going with my girl from Tokyo, I live in Hawaii. We’re both in our mid-20’s.

What do you think of this Mexico City idea? I KNOW there are a million better places, but where should I go? The more I think about Mexico, the more I don’t want to go!..

Thanks!