Acknowledging that Thrawn had long been considered by Lucasfilm when developing projects, Filoni said that in particular, the character had been on his list of potential villains when developing "Rebels". He explained that unlike how the character Ahsoka Tano has been a foil for Darth Vader in previous seasons of "Rebels", "There's no one to defend Rebels against Thrawn. We want to treat him like a big-time villain, as much as Darth Vader, but on the strategic, military side of things."