[ He's unaware of Crowley's status. The last Castiel saw of him was in the church. Beyond that he didn't know what had happened to him. There was one thing that Cas did know though and that was Dean. He knew Dean's resourcefulness and his desire to turn the tables on the demons. He would have wanted to keep Crowley close at hand to get information from him. Sam's not the torturing type, but Dean was a torturer in Hell. Castiel had seen first hand what Dean looked like after falling prey to that down there. He tried to ignore it, but he couldn't. It was always there below the surface. If he could extract information from Crowley then he'd keep him close. Alive. Unchanged. It's what Castiel would do if put in that situation. ]

I believe I can. Dean's most likely using him for information of sorts. I don't believe he's in any position to stand in your way. [ The way she says his name leads him to believe she's not on the best terms with him. Castiel understood that desire to kill the man. Him and Crowley have been dancing around the idea of killing one another for a long time now. Ever since their alliance for the souls. Crowley was "screwed over" in that deal and Castiel walked away with ultimate power. Unfortunately that power was gone now, but Crowley's hatred for Cas isn't.

He's not sure if he's overly fond of the idea of going head to head with Crowley if that's what she wants. Crowley was responsible for Meg's death though and maybe it was important that he dealt with that. ] Though I have no problems with you killing him. He's not my--[ He pauses to search for how he wants to phrase it. Dean had a million and one ways for how he would. Cas simply had what he could remember. ] biggest fan. I "screwed him over" previously. Ever since then he's wanted revenge. He's been nothing, but a thorn. If you wish to kill him then I can help.