The Sith Lord's Helmet Deliberately Parallels Darth Vader
As soon as Osha puts the Sith Lord's helmet on, the scene mirrors the creation of Darth Vader. Osha's breathing through the helmet sounds similar to Vader's mechanical breathing. This symbolizes the birth of a new Sith apprentice. Qimir desires a pupil, an Acolyte, and wants to harness the power of two. Osha wearing the helmet signifies her changing allegiance, just like Vader in Star Wars: Episode III – Revenge of the Sith.
Unlike Darth Vader, neither Qimir nor Osha needs the helmet to survive. Vader's helmet kept him alive after his duel with Obi-Wan Kenobi in Revenge of the Sith. The helmet also parallels Kylo Ren's in the Star Wars sequel trilogy. Kylo didn't need a helmet, but wore it to honor his grandfather and intimidate his enemies. The Acolyte has subtly mirrored Qimir and Kylo Ren's characters, including using Kylo's theme music, so this parallel is not surprising.
Osha Is Acknowledging The Lure Of The Dark Side
Osha is being lured to the Dark Side. Though she insists her connection to the Force is lost, Qimir offers a different perspective. Emotions the Jedi suppress – anger, fear, loss, desire – can awaken the Force. Osha is wary of Qimir's motives but wants something – truth, freedom, and the Force. The dark side can offer all of that and more.
Qimir preys on Osha's desire to belong and offers her the chance to restore her connection with the Force. Osha has lived a tragic life, full of pain and sorrow. She lost her coven, believed her sister perished, joined the Jedi Order, left, and watched loved ones die. Qimir, while ruthless, is also empathetic. There is a bond between them that Qimir can convince Osha is worth exploring.
Osha Is Reconnecting To The Force... Through The Dark Side
The helmet is a key part of Qimir's plan. He tells Osha it acts as a sensory deprivation mask, like they used to train with in the Jedi Order. For both Jedi and Sith, it strengthens their bond with the Force, allowing them to connect to their power without distractions. The helmet functions similarly to Master Torbin's Force field in The Acolyte episode 2. No interruptions – only the wearer's mind, the Force, and their emotions matter.
These sensory deprivation helmets are normally used for training – Luke Skywalker wears one when Obi-Wan Kenobi trains him in the original Star Wars movie. Qimir wears his helmet at all times, even during The Acolyte episode 5's massacre. This means he's not just hiding his identity and intimidating opponents; it makes him stronger. He's driven solely by the Force and the Dark Side.