One of the most shocking moments from The 100's final season started right at the season premiere, with Season 6's primary antagonist Russell Prime having his consciousness murdered by the evil Sheidheda, seizing control of Russell as his new host body with much of colony of Sanctum unaware of the switch. With the Dark Commander, a cruel dictator from Earth's past, resurrected as the head of an overzealous cult, the villain steadily built up his power base, pitting factions against one another until he was discovered by Indra and John Murphy and had the Mind Drive cut out of his neck, preventing him from further resurrections.

Despite this setback, Sheidheda has relished the challenge presented to him as he squares off against Indra and Murphy, leaving a trail of bloody victims in his wake as he stakes his claim to the throne of a new world for the last remnants of humanity. In an exclusive interview with CBR, actor J.R. Bourne shares how he learned and adapted to in transitioning from Russell Prime to Sheidheda at the start of Season 7 and the thrills of portraying an unrepentant villain.

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How quickly did you find out for Season 7 that you were going to play a completely different character for most of this season, J.R.?

J.R. Bourne: I found out midway through Season 6. [Showrunner] Jason Rothenberg called me in and said "This is what we're thinking..." and I picked up my jaw off the ground and they said "Does that interest you?" and I said "Yes! Yes! Yes!"

Obviously, Russell Prime was an antagonist in Season 6 but you're going full tilt evil in Season 7. How has it been playing this very different, but no less sinister, villain?

Bourne: I've got to say, as an artist, it's just been an absolute freaking blast because there is no fighting against a moral compass. Russell had a huge degree of humanity, he loved his family, he had a daughter, he created a world, in his mind, that was a utopia. What he was doing, he thought, was for the good of mankind. Sheidheda...[Laughs] there is nothing to struggle against other than "How quickly and how fast am I going to get to that throne? Let me set the tone here, let's make Sanctum a real place to live in." in his own demented version of that.

One of my favorite scenes this season was between you and Richard Harmon playing off each other over a chess game. You've also gotten to play off Idina Porter's Indra this season too. How has it been working with those two actors?

Bourne: Richard and I had a lot of fun prepping that scene. We knew it was coming so we were really excited way prior, we knew there was something long and lengthy coming for the two of them. On the day [of filming]...it was just a highlight of my entire career, working with both of those individuals in Idina and Richard, getting down into the crazy mindspace of Sheidheda and his more limited history with Murphy but a very deep-rooted and long history with Indra.

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The first half of this season, you've been more of a manipulator, making deals and playing sides. How has it been playing up that Machiavellian side of the character and literally cutting loose once we went into the midseason break?

Bourne: We found the tool right out of the gate with Russell's book and he took his time studying. As much as he wants to hurry his way to the throne, he knows that's not the way, that's not what he's going to do. So the studying of Russell's book, not just the layout of how Sanctum is built but the history of these people, what is there, what it's based on, what the relationships were and are are all tools for him setting up the board game.

But cutting loose, and that's a great sort of analogy to use, now we're past the faithful, we'll cut them loose, and now the game really does begin. As much as Sheidheda can respect and even feel a degree of defensive, twisted, warped love for someone, it's Indra. She is a reminder of what he did when he was commander to her clan, to her parents, who she had grown up to be. She's a worthy opponent and he knows that. That's why we'll see in [Episode] 10, coming straight out of getting rid of the followers, going into 10, the next, big move is making sure there is a meeting of the minds, so to speak, but in a Sheidheda-Indra way and see what they're both fiercely accomplished and good at as necessary and we'll see that in 10.

Murphy is [held] in lesser degree, but he absolutely sees Murphy for who he is and what his role is within his own people and community. And he likes Murphy, you know, he likes the little, twisted twinkle in his eye.

I feel like that's the only reason he let him live at the end of that chess game.

Bourne: Oh yeah, that is exactly [it]. Once that Mind Drive is taken out of his neck, he realizes "Okay, that's it for resurrections. I'm still going to become Commander, I'm still going to sit on that throne but I'm going to have one hell of a time on my journey there, I'm going to have fun." I always toyed with does he see himself in a very young version of Sheidheda in Murphy? Could I whip Murphy into a powerful force to be reckoned with? He already is, they refer to Murphy as a "cockroach" but I think that that thing Sheidheda sees as weak is Murphy's heart, Murphy's moral compass. He didn't want to kill him.

Did you ever miss playing Russell Prime, this more nuanced, sympathetic character, or, once you got into Sheidheda, you were all set moving forward?

Bourne: Russell was done...it was time to put him to sleep. He lost everything. I think that was his true sort of relationship to weakness, his fear, it was done. That's why he asks Clarke "How do you do it?" He was just done, he was like "I'm going to stare at the pictures of what I've done and what I had, they're all gone. What do I have left?" Russell, for me as an artist, was dead as well. It was easy to put him to rest and be like, "Now we got this guy to play with! And now he's fully alive!"

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I feel just as things were getting good, a lot of the other characters went off-world. Is there any character you would've loved more time playing opposite off of?

Bourne: That's a great question...when I think of every single one of them, I would have a joy going toe-to-toe with them. I would have a joy playing with them all. For seven freaking years, they've all so firmly planted who those characters are and the history that they're bringing at this point of the show. I would've had an absolute incredible time playing with any one of them.

Was it easy for you to jump in last season or did you feel like the new kid at school with all those relationships having been established?

Bourne: But my own sort of wanting to make things harder than they are, I would've loved it to be more difficult to get in, Sam, but no, they fully embraced me. Sam, I feel like genuinely, on and off set, there were moments with all of them that I really carry closely to my heart. It's a good, genuine group of people so, yeah, they welcomed me with open arms.

J.R., what can you tease about your character as we get into this last stretch of episodes?

Bourne: I think you're going to see Sheidheda live every single moment like it's his last and have fun. And as much our heroes are going to create obstacles on Sanctum and try to bring this motherlover down, he's going to have nothing but joy and energy and a sense of his demented definition of love in every single thing he does and make sure that that throne is his.

The 100 stars Eliza Taylor, Marie Avgeropoulos, Bob Morley, Lindsey Morgan, Richard Harmon, Tasya Teles, Shannon Kook and J.R. Bourne. The series airs on Wednesdays at 8 p.m. ET/PT on The CW. The final season returns after a two-week hiatus on August 5.