Which Billy Dee Williams character did Grand Admiral Thrawn face off again?
Grand Admiral Thrawn:  Thrawn faces off against classic "Star Wars" characters Luke Skywalker, Princess Leia, Han Solo, Chewbacca, and Lando Calrissian in the "Thrawn" trilogy (1991–1993), but is ultimately defeated. Lando Calrissian:  He is portrayed by Billy Dee Williams in "The Empire Strikes Back" and "Return of the Jedi", and will be played by Donald Glover in the upcoming Han Solo standalone film.
Lando Calrissian