User blog comment:NaiflidG/Relating to Alastair in "On the Head of a Pin" and "Caged Heat"/@comment-24199167-20141116191139/@comment-11331875-20141117052957

See, that's something that I don't like that the show didn't address with Demon!Dean -- he actually demonstrated very few powers, like telekinesis, with the Mark. We can safely assume that he was the strongest demon left on Earth at the time, since all evidence implies that he was stronger than Crowley, the King of Hell, but they don't show that; what they showed was Demon!Dean goofing off, shanking grunts, and acting as just a more callous version of Dean most of the time. (I heard that that might've been because Jensen played Dean so dark last season that he didn't want to play him even darker this one.) To my knowledge, there's no real concrete statement on how Demon!Dean would figure into Hell's hierarchy at that point or how powerful he was, so it's hard to say that Demon!Dean, a newborn demon, is equal to Cain, one of the first demons, in power and rank. Demon!Dean seems to have been stronger than Crowley, at least, but we don't know how he'd fare against Cain -- would not having the Mark weaken Cain? does Dean being much younger than Cain mean he hasn't developed all of the powers that Cain has? does the fact that Cain was given the Mark by Lucifer himself during Biblical times, and Dean was given it by Cain a few months ago, affect their respective power levels? There's a lot of variables they left unaddressed (so far) about Demon!Dean's potential. (There's a spoiler about this that might figure into the discussion, but I don't know if you want to be heard it yet or not.)

Eye color does generally mean rank. That's why all crossroads demons have red eyes, all soldier and minion demons have black eyes, etc. Dean and Abaddon (maybe Cain, too) are black-eyed because -- according to Cain -- Knights are technically classified as the soldiers of Hell. I'd've much preferred it if the Knights had been given different eye colors -- to indicate more clearly that they're not grunts and who'd they'd actually be more on the level of -- but ah well, I suppose it makes enough sense as is in this topsy-turvy canon. (Though Cain being white-eyed or even yellow-eyed, instead of black-eyed like his creations, would earn Carver a few brownie points from me. Hint hint, nudge nudge, Carver.) I might open up another blog soon to discuss in detail where the Knights might have ranked in the hierarchy back when they and all the other major demons were all alive.

You're right in saying that Cain was totally immune to Ruby's knife while Alastair wasn't, but so was Abaddon, and she doesn't seem to have been as powerful or high-ranking as Alastair. Cain is only as powerful as he is -- and only immune to the knife as he is -- because he had the Mark (and Abaddon because she was made by a demon who had the Mark), which is a major game-breaker among demons that makes even humans who have it more powerful than the Knights of Hell. I'm afraid that I don't understand why you brought up Alastair's vulnerability to the knife and Cain's immunity to the same, in the first place. Is it because we were discussing Alastair's vulnerability to the knife below, or was it to imply that Cain was probably stronger than him, or...? 'Cause I don't know what I'm responding to.