Mueller Simka operates as a subordinate to Jacob Halm within EX, the organization controlling Eden. She displays steadfast allegiance to EX and actively aids Eiji Takanaka during his initial integration, reflecting a well-intentioned nature. Her significance grows during EX's conflict with the netjackers and the emergence of Project Heaven's secrets. Mueller defies Project Heaven, resulting in direct confrontation with EX's leadership. This dissent leads to her elimination; Bishop Won Dai brutally executes her using a mechanical arm. The circumstances of her death are described as exceptionally brutal, with narrative commentary indicating the extremity of her fate was undeserved given her consistent supportive and loyal actions prior to her opposition. Her death stems directly from her dissent against EX's plans.