Socom  

The character you're referring to is known as Cz, an artillery-type Peacemaker who appears later in the series. While his personality shares some similarities with Steyrs, he is not as sadistic or overly determined to kill people. In one episode, while waiting for Pacifica to arrive at Leinwan, Steyr suggested starting to kill people, but Socom intervened and said that such behavior was unnecessary. Despite this, Cz harbors a deep-seated hatred towards humans or feels no particular desire to protect them. He is partnered with Steyr. In the final episode, Cz was destroyed by the three Gigas when they used their light lances to slice him into three sections.