He created an pleasant and likeable character in Palpatine 's public face . Darth Sidious is the Chancellor 's Sith alter ego . The prequels had him play two faces to his character ; he re-created his diabolical interpretation of Palpatine from Return of the Jedi when playing Darth Sidious , the Chancellor 's Sith alter ego , but created an attractive , pleasant , and seductive character in Palpatine 's public persona .