Is Annie bad in attack on titan?

Answer 1

I can't tell you much without spoiling the show, but I would say to stick with your gut when it comes to Annie. Yes, she is a large part of the plot later on, and yes, she does some bad things. Somehow, she justifies them, though, but not very well.

Answer 2

Annie has a secret mission, as part of a team with Reiner and Bertolt. This mission isn't fully knows, but it involves claiming the titan-controlling power, 'The Coordinate' from the current holder, Eren.