Beatrix is the commander of the infamous Stasi TSF battalion "Werewolf," notable for their ruthless suppression of anti-government rioters and crushing potential rebellions before they began.
She is a former friend and former military academy classmate to Irisdina, with whom she always had a strong rivalry. She is currently field testing a next-generation Soviet TSF--the MiG-27--and setting in motion a series of events that will bring even more power to the Stasi.
In contrast to the visual novel, Beatrix in the anime is a sadistic sociopath who delights in the pain and deaths of those around her. Instances of this are in such scenes as the anime original mass execution, where she smirks viciously as her victim's viscera splashes on her face. Another instance of this was during her torture of Marai, where it was implied that she had enjoyed the experience. Even her own soldiers weren't immune to this, as Beatrix took great pleasure in Lise's mental turmoil over her brother and the deaths of other Werewolves. Beatrix was only truly happy at the expense of others.
Another difference was her relationship with Axmann and Schmidt. In other material, Beatrix, Axmann, and Schmidt detest one another, and Beatrix avoids them whenever possible and will sometimes subvert or disobey their orders if she can. In the anime, she has a good working relationship with them and acts as their willing attack dog.
Beatrix kills Erich Schmidt after she finds out Schmidt is a KGB agent who was using East Germany for the Soviet's benefits. She then becomes the de facto leader of the Stasi.
She is killed by Theodor during the coup d'etat to remove the Stasi from power.
Unless dealing with Irisdina, Beatrix in the visual novels remained calm and collected. She was somewhat detached and cool during her final battle with Theodor, and even right before her death, smiled serenely at the incoming CIWS. In the anime however, she devolves into a snarling, bloodthirsty berserker, and uses her last moments after being mortally wounded to taunt Theodor.
