As Comic Book reports, George Lucas envisioned that with Emperor Palpatine's death, the galaxy would plunge into chaos, and the main antagonist from the first episode, Darth Maul, would emerge from oblivion alongside his apprentice Darth Talon.
The filmmaker himself once shared these details. In this new trilogy, Darth Maul wouldn't just be your typical assassin with killer lightsaber skills. He'd transform into a full-blown crime lord and "galactic mafia godfather." The lower-body-missing Maul would get cybernetic spider-like legs to boot. Darth Talon, who once appeared in the Star Wars comics, would play the same role beside this new villain that Darth Vader once played beside Palpatine.

Source:
imdb