According to CBR, sources are saying that this character is going to be Barriss Offee, the Jedi Knight from The Clone Wars who betrayed the Jedi Order and framed Ahsoka for a crime.
In The Clone Wars, Barriss and Ahsoka were padawans at the same time with Ahsoka training under Anakin Skywalker and Barriss training under Master Luminara Unduli.
This could be in the upcoming Ahsoka series starring Rosario Dawson as the titular character.
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