Walter Sheridan

Walter "Wally" Sheridan is the main antagonist of XIII. He is the younger brother of the deceased president, William Sheridan, a United States Senator and eventual presidential candidate, and Number I, leader of the XX. He is the mastermind behind the assassination of his older brother, as well as the attempt to install a authoritarian regime in the United States through operation Total Red. However, his plan is thwarted by Jason Fly, and by the end of the game he is the last living member of the XX besides Kim Rowland.

Background
Walter Sheridan was born the second child of his father, Henry Sheridan. As a member of the Sheridan political dynasty, Walter and his older brother William, were given many opportunities to gain successful careers. However, Walter, 12 years younger than his brother, always felt like he was living in the shadow of William. This feeling was made even more poignant when William was elected as President of the United States.

Walter had a brief tenure as a university professor, where he fell in love with one of his students, Kim Carrington. With Kim, Walter fathered an illegitimate child, Colin. After distancing himself from Kim, Walter become absorbed in the world of politics, climbing the ranks to become a senator. Eventually, Walter was contacted by Calvin Wax, then advisor to Vice President Joseph Galbrain. Wax was able to manipulate Walter to resent his brother and his ideas of how the nation should be run. Together, they sought out people in the highest positions of power to form a group that would rule America, the XX.

Along with influential people, Walter also sought out Kim and kidnapped Colin. Using Colin as ransom, Walter inducted Kim into the XX as Number XVII, and ordered her to infiltrate the American Intelligence Community to serve as a double agent, spreading misinformation to aid in hiding the existence of the Conspiracy. Kim later married Steve Rowland, and brought him into the Conspiracy as Number XIII. Due to Rowland's elite training in the SPADS under fellow conspirator Seymour McCall, Rowland was selected to carry out the assassination of William, setting Walter to run for President.