Just like in The Clone Wars, Maul continued spreading his special brand of trouble in Rebels, but it all ended when he went to Tatooine to have his re-match with Obi-Wan Kenobi, only to be swiftly cut down by the Jedi Master, for good this time.
Found by his brother, Savage Opress, Maul was restored to his original self, and together they began building a criminals empire called The Shadow Collective.
For those who didn’t follow along with The Clone Wars and/or Rebels shows, after his defeat in The Phantom Menace, Maul, through sheer will and the power of the Force, kept himself alive and ended up on the junkyard world Lotho Minor.
He’d lost most of his memories, but he was still consumed by his hatred of the Jedi.