Supernatural's Castiel will play a major role in removing Dean's Mark of Cain.

Jensen Ackles Teases 'Supernatural' Mark Of Cain Problems, Dean Falling Down The 'Rabbit Hole'

Cas (Misha Collins) helped Dean ditch his black eyes, but the angel recently learned that the Mark still has a strong hold on it's bearer. Dean's (Jensen Ackles) little murder spree during "The Things We Left Behind" left Cas looking horrified, and Collins character will soon intensify his efforts to cure the ailing hunter.

"Cas is intimately involved in trying to remove the Mark," Collins informed The Hollywood Reporter. "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."

Guest Stars Announced For Cain's 'Supernatural' Return, Tim Omundson To Appear In Episode 14

Now that Cas has replenished his angel juice, the heavenly soldier is out of mortal danger for the moment. Crowley's (Mark Sheppard) little gift will help keep Cas' lights on for some time, and the rebel angel will use that time to focus on keeping Dean from spiraling out of control.

"In this stretch of the season arc, the focus is on Dean, and Cas' health is not nearly as much of an issue," Collins said, according to The Hollywood Reporter.

Find out more when Supernatural returns to The CW on Jan. 20. Click the video below to see a preview for "The Hunter Games."

Tags: supernatural television the cw