Ewan McGregor Felt "Real Fear" of Hayden Christensen's Darth Vader in Obi-Wan Kenobi

Fear may be the path to the dark side, but Ewan McGregor felt "real fear" seeing Hayden Christensen suited up as Darth Vader on the set of Obi-Wan Kenobi. A decade after Obi-Wan's fiery lightsaber duel with the newly christened Darth Vader in Star Wars: Revenge of the Sith, master and padawan will reunite for what Lucasfilm president Kathleen Kennedy has billed as the "rematch of the century." Set another nine years before Obi-Wan and Vader's fated final encounter aboard the Death Star in A New Hope, the series premiering May 27 on Disney+ marks McGregor's — and Obi-Wan's — first time seeing the Sith Lord's life-saving suit of black armor.

"He really is [terrifying]," McGregor said of Christensen's Darth Vader on BBC One's The One Show. "I had a moment because I, obviously, in the [Star Wars prequels trilogy], I didn't work with Darth Vader."

When rehearsing a scene between Obi-Wan and the now fully-armored Darth Vader, McGregor recalled, "He had the helmet on. In the scene, he comes up from behind me, and we were getting ready and I was getting my makeup done. They'd yelled 'action' and I start walking down, and I turn around, and there's Vader coming at me (laughs). I swear, I had this jolt of absolute fear, real fear. I'd never had that in acting before."

"I was like seven years old again going, [gasp]," he continued. "The face, the helmet coming at you. Hopefully, [the audience feels] something similar, I hope." 

In a previous interview, Christensen said it was "surreal" donning the armor for the first time since 2005's Episode III – Revenge of the Sith. 

"It's an incredible costume, and putting it back on again brought up a lot of emotions for me," Christensen told On Demand Entertainment of his 17-years-later Star Wars return to a galaxy far, far away. "It's amazing to get to wear it, it's an honor to put it on. Just a lot of fun, really."

Starring Ewan McGregor, Moses Ingram, Rupert Friend, Joel Edgerton, Bonnie Piesse, Indira Varma, Sung Kang, O'Shea Jackson Jr., Benny Safdie, Kumail Nanjiani, and Hayden Christensen as Darth Vader, Star Wars: Obi-Wan Kenobi premieres with two episodes Friday, May 27, on Disney+. New episodes will air on Wednesdays beginning June 1.