This was not how it was supposed to end. Struck down by his Master, perhaps. By a mere padawan? No.
Still, Maul reveled in the cold comfort of the Dark Side as he became one with the Force. He kept watch over Sidious from his place in the Force. Kept watch over the padawan who had touched the Dark when he slew Maul. Found satisfaction in watching the fall of the Jedi.
He watched with horror as Sidious was destroyed. Felt his own presence begin to shatter as Vader was Redeemed.
This was not how it was supposed to end.