Darth Maul

Darth Maul is the former Sith Apprentice of Darth Sidious (Emperor Sheev Palpatine).

Girl at War: Spark of Rebellion
Ezri has a vision of Darth Maul; however, he is identified as a "red-faced, tattooed alien" Ezri had never seen before as she witnesses him get killed by Obi-Wan Kenobi