Despite his untimely "death" at the end of The Phantom Menace, which was cut in half by Obi-Wan Kenobi and sent tumbling into the depths of Naboo, Star Wars still can't seem to find Darth Maul. In Star Wars: The Clone Wars, Lucasfilm decided that Palpatine's former Sith apprentice had indeed survived the fall, first as a crime lord who at one point even ruled Mandalore from the shadows. Most recently
The villain's return in the Prequel Trilogy was not achieved overnight. It took over a decade, from his fatality in the 1999 blockbuster to his surprise return in 2012 in The Clone Wars episode "Brothers," to bring him back to the galaxy far, far away.
Maul would have returned sooner and in a far less probable state if George Lucas had gone with his original plan for the Prequel Trilogy, according to Clone Wars writer Henry Gilroy. Grevious would have exposed his true identity to Obi-Wan in Revenge of the Sith.
Grievous first appeared in Genndy Tartakovsky's Clone Wars micro-series as a Separatist General obsessed with repurposing his body parts with droid equivalents and collecting the lightsabers from the Jedi he'd killed on the battlefield. He has a fierce rivalry with General Kenobi in a final duel in Revenge of the Sith that culminates with the villain being burned to a crisp.
Lucas' thought may seem now, but the Maul connection made sense to Gilroy at the time. "[Maul] is reduced in half, and he's in this robot body or whatever."
Grievous does appear in Revenge of the Sith with a genuine hatred for Obi-Wan, which, if he had been Maul all along, would have been an easy enough grudge to understand. When Maul finally reappears in The Clone Wars, he was determined to return to Kenobi and the Jedi, and was eventually refitted with cybernetic parts similar to Grievous.
Gilroy is content with the way things turned out in the end: “I’m glad Grievous is his own thing anyway, but I thought it was interesting that the concept guys almost talked George into it.”
The question remains whether or not Maul will ever return in live-action? There are still plenty of stories to tell about the villain between the conclusion of the Prequel Trilogy and his death at the hands of Kenobi in the Rebels animated series. And if there is one thing we’ve learned in the last two decades, it’s that you cannot keep a good Star Wars character down.