The Jedi may wield a lightsaber but on the set of Star Wars: The Last Jedi, Rian Johnson’s smile was just as powerful.

The director’s little-kid perma-grin never seems to leave in an exclusive behind-the-scenes video for The Last Jedi (in theaters Dec. 15) making its debut at usatoday.com. “It’s hard to go too long on set without having something remind you you’re standing in the middle of your Kenner toys you grew up with, the spaceships and everything,” Johnson says. “There’s something every hour on the hour that makes you zoom back and think, ‘I’m the luckiest person on the planet right now to be doing this.’ ”

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The new footage shows Johnson trying on a Stormtrooper helmet and giving Chewbacca vocal directions but also features cast members talking about their fearless leader, including sweet thoughts from the late Carrie Fisher: “He has flaws in other areas. I just don’t know about them.”

We talked with Johnson about what’s up with Luke Skywalker for our holiday movie preview, plus asked about some other important Last Jedi players:

Q: The journeys of new heroes Rey, Finn and Poe streamlined at the end of The Force Awakens. From the looks of the Last Jedi trailers, it seems like they’re each going their own way again.

A: When I first read the script of The Force Awakens, I was like, "I feel like I know these characters instantly." And now we get to kind of put them through a meat grinder. (Laughs) And for me, part of that meant that we had to make things as hard on each of them as possible: At least part of the movie, they don’t have their friends around. They’ve got to figure things out for themselves. They’ve got to be faced with whatever the toughest thing each of them can be faced with, and they’re not going to have their buddy there next to them to get them out of it, necessarily.

Q: Rey's off with Luke, but Finn has to go undercover and put on a First Order outfit again. Does he freak out?

A: (Laughs) Man, I would if I were him. Just think of the moral courage it took, and how much just physically it took, to get away from the First Order. It’s that thing of coming back to "What’s the thing that would be toughest to throw at each of these people?" And to go back into the machine, to put that uniform on again, made a lot of sense to me.

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Q: Does Leia see Poe Dameron as the future leader of the Resistance?

A: Yeah, I think so. He’s also got some growing to do. Poe’s got to grow. She definitely saw that potential in him and in The Last Jedi, we dig into that more. We’ve seen how heroic he is and now we’re going to see him challenged in terms of stepping up to the next level. It takes more than heroics to be a leader, or so I’m told.

Q; Is it going to be an emotional couple months getting ready to release the movie and seeing it again with Carrie as a part of this universe?

A: Having these scenes in the film recontextualize tragically with her not being here anymore, it’s incredibly emotional. For the next few months, seeing the fans … process the loss and celebrate her as Leia one last time, it’s going to be intense. I think it’s going to be really sad but really joyful, I hope. She really kicks (butt) as General Leia, and I’m happy for that.