sure Ahsoka defeated maul but she did not kill him, and to be the rightful owner of the dark saber you have to kill the owner not defeat them so Ahsoka is not the rightful owner
It says in season 3 of Mandalorian "She defeated the enemy that defeated me." and says she is the rightful owner of the Darksaber. you only need to defeat them.
Rey is the rightful owner of the Darksaber. Huh? Pre Visla owned the Darksaber, then Darth Maul killed him. Then Obi-Wan killed Maul, then Vader killed Obi-Wan, then Palpatine killed Vader. Then "Somehow, Palpatine returned," and Rey killed Palpatine. Therefore Rey is the rightful owner of the Darksaber. Jesse, what the frick are you talking about?