Survey Corps

The survey corps are the offensive group in the whole series. They are also pretty much the only group that shows up. Their leader is Erwin Smith and as head of their Special Operation is Levi Ackerman.

History
Unlike the series they are portrayed as a really weird group. To begin with it's mentioned various times that when they are fighting titans the higher ups are either stoned or high. Meaning they are either drunk or drugged. Bearing resemblance to the series they are skilled at what they do and tend to do their job efficiently. Of course the rough treatment of the initiates is also present here as well as in the book. We can see the use of swear words from some characters that don't actually fit the attack on titan series, however this adds a lot humor.