 However, when Jedi Master Mace Windu confronts Palpatine, Skywalker comes to Palpatine's aid and helps him kill Windu.Knowing that his involvement in Windu's death will cause him to be expelled from the Jedi Order, Skywalker is left with no choice but to become Palpatine's third apprentice, Darth Vader.Palpatine declares the Jedi to be traitors and all but exterminates the Jedi Order in a massive galaxy-wide slaughter.