The CW star talks with THR about the ongoing mark of Cain mythology, a key new relationship for his character and whether he'll direct again

Ever since The CW's Supernatural first introduced the angel Castiel (Misha Collins) in the season-four premiere, he has been vitally important in the overall mythological story arc for the elder Winchester brother, Dean (Jensen Ackles).

He literally saved Dean from hell, and now, a half-dozen years later, he is playing the same pivotal role. Earlier this season, Castiel aided Sam (Jared Padalecki) in saving his brother from being a demon, and as both the character said on the show and Collins shared with The Hollywood Reporter, that fight is far from over. Residual effects from the mark of Cain branded on Dean have already begun to show themselves, and as the series moves into the second half of the season, it is a storyline that comes back in a big way.

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"Cas is intimately involved in trying to remove the Mark,” Collins tells THR.

"It's definitely shaping up to be a team effort, but Cas will be instrumental in 'de-marking' Dean … Getting the mark gone is an important mission for the rest of the season, and I think that that struggle is taking the fore[ground] in terms of … illness … In this stretch of the season arc, the focus is on Dean, and Cas' health is not nearly as much of an issue."

Collins added that though Castiel is again operating on stolen grace — aka borrowed time — his new grace is strong now and will remain so for "the better part of the season."

"This gives him a stay of execution, so he's got disposable batteries. He's got a new set; they're Duracells; they should last for a little while [but] not forever. So it will be an issue that resurfaces again, [but] it takes awhile," Collins said.

And it's not something Castiel is dwelling on. Although he seemed to make his peace with a less than favorable fate when his last grace was wearing out, he is not in that mindset right now. In fact, Collins is pretty confident in saying that Castiel is "sick and tired of making deals with the devil and will [try] not [to] make that compromise again." But between the search to truly cure Dean and the resurfacing of his vessel's daughter, Claire Novak (recast as Kathryn Love Newton), he has his hands full with other things for now anyway.

Claire turns up in "The Things We Left Behind," the ninth episode of season 10, and will stay for two episodes (for now). As Collins describes her, "She's a 17-year-old kid; she's independent; she's had a rough go of it because of me taking her dad, among other things, and that just makes for a really interesting dynamic." She's also living in a group home that she convinces Castiel to break her out of — only to run away from him once he does.

"He's definitely impacted emotionally by Claire, and it's hard to say what the primary motivating forces is with Castiel are, but I think that one of the large ones is not that noble: it's just guilt. He feels bad for having f—ed up this girl's life, and he wants to help her, but she is now a typical teenager and doesn't really want anything to do with him," Collins said.

"It's something new for Castiel, especially new for him as an angel. He had a little bit of experience with some of that stuff when he was human, but now having to sort of engage a human being on a very personal level that doesn't have anything to do with fighting supernatural forces is very new for him," he added. "And I think his experience as a human does give him much more empathy and make him want to try a lot harder to make it work."

Collins also hopes Claire becomes a key recurring character who will pop up again — perhaps even in an episode for which he steps behind the camera. Like Ackles, Collins has taken his turn in the director's chair for Supernatural (season nine's "Mother's Little Helper"). While he has no plans to do so again this season, the actor hopes the show returns for an 11th season so he can take another trip behind the camera.

"There's a little more directorial latitude on the monster-of-the-week episodes. Those are the episodes that have broken the fourth wall or were shot in black and white or sienna or they kind of go in weird directions with those, so I would love to do one of those," Collins said.

In the meantime, Collins is keeping busy not only as Castiel on screen, but also off screen with his Random Acts nonprofit organization, with which he is prepping to build a school in Nicaragua and turn into the "Kickstarter for charities.".

Supernatural airs Tuesdays at 9 p.m. on The CW

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