The third season of "Star Wars Rebels" will feature a new antagonist, and a familiar Sith will also make a return. The first episode of the new season is expected to arrive on September.

According to reports, aside from Darth Vader, there will be another villain that will be introduced and this is Grand Admiral Thrawn. This season, he will give the rebels a hard time when they try to accomplish their missions.  

Grand Admiral Thrawn's character first came to life when he appeared in the expanded universe (EU) of "Star Wars" which is now non-canon. He was created by Timothy Zahn. The creator of the show, Dave Filoni, wanted to adapt the character into the animated series since he was attracted to Thrawn's persona. Furthermore, he also liked the art design of the character.

Darth Maul will also be returning in the third season and he is still persistent in his attempts to lure Ezra to become his Sith apprentice. There are speculations that there will be an epic battle between him and Darth Vader. In addition, there is a possibility that he knows a lot of information about the dark side which he will soon reveal.

As stated in reports, the first episode will be titled "Steps into Shadow," and a new character named Bendu will be introduced in the premiere. He is a gigantic entity that seems to know a lot about the force, but he does affiliate himself with neither the light side nor the dark side. However, it is still unknown if he will help the rebels or not.

There are speculations that he will be the one to guide Kanan with the Force. During the season 2 finale, the character was blinded and it seems that Bendu will teach him how to connect to the Force even without his sight.

The third season of "Star Wars Rebels" will premiere on Sept. 24 on Disney XD.