The winning entry in the "Darth Who Contest" was the official Sith name of a major character revealed in the book Legacy of the Force: Sacrifice, the fifth in the Star Wars: Legacy of the Force series. The contest ended at 12:00 am EST on December 1, 2006; according to the February/March 2007 Del Rey Star Wars newsletter, 8500 entries were received. The top five names were chosen by the editors at Lucasfilm and Del Rey, and the authors of the Legacy of the Force series. Their selections were announced on January 23, 2007.
According to The Essential Reader's Companion, Jacen's placeholder Sith name under the Darth Who Contest was Darth Kallus.
The contest was open to all registered members of the Star Wars official site who were American citizens over the age of 18. Each member was able to submit one name only. The contest lasted from October 3 to November 30, 2006. Aaron Allston, Troy Denning, and Karen Traviss selected the top five entries, which were then posted on the official site on January 23 and remained on the site for voting until February 27, 2007. During that time, registered members of the official site could vote for the winner.
It had been originally thought that the Legacy book series might determine whether or not Jacen Solo would become Darth Krayt of the Legacy comics (a common fan theory at the time before the book was released), but the announcement of the contest altered this concept, as the Sith name was determined by contest and Darth Krayt was not one of the potential names. The identity of Darth Krayt was later revealed in a Legacy comic as the former Jedi Master A'Sharad Hett.
The winner, as announced in Legacy of the Force: Sacrifice, was Darth Caedus. In the acknowledgements in the beginning of the novel, Del Rey Books and Lucas Licencing Ltd. thanked the winner, Tawnia Poland, for contributing the name. There was also a thank you to all the fans who took part in the Darth Who contest.