Honestly the best villain revealing speech ever.
This is my favorite Ruby moment ever. Because you know what? She is awesome. It’s just like she says:
"You don’t even know how hard this was! All the demons out for my head. No one knew. I was the best of those sons of bitches! The most loyal! Not even Alastair knew, only Lilith! Yeah, I’m sure you’re a little angry right now but, I mean, come on, Sam! Even you have to admit: I’m, I’m awesome!”
Seriously, do you know how hard that must’ve been? She basically had all of hell gunning for her for two years. Once the angels got involved, they were after her too. And it wasn’t like she was getting a ton of support from anywhere else, either— Dean was outright hostile to her, Sam kept blowing hot and cold towards her, and Lilith? Well, if she screwed up, it wasn’t as if she could count on Lilith to help her out. Ruby was literally all on her own.
And she did it. She fooled the Winchesters (Dean didn’t trust her, and even Sam was suspicious, yeah, but it still worked). She got around heaven. She survived Alastair and tons of other demons.
And that? That’s something she deserves to brag about. That’s the kind of manuevers you get serious props for.
And at this point, that’s what she’s expecting. Because she’s done it. She’s gotten Lucifer out of the cage. Azazel’s dead, Lilith’s dead, Alastair’s dead, Meg’s been essentially MIA lately, Crowley’s a turncoat— so who’s at the top of the demon hierarchy? Who’s there to greet Lucifer when he gets out of the cage? Who’s the one who got Sam to open it in the first place? Ruby.
So of course she’s ecstatic. She just brought back her god and that alone is worth celebrating. But beyond that, think of what she says to Sam:
"You set him free. And he’s gonna be grateful. He’s gonna repay you in ways that you can’t even imagine."
Honestly it’s somewhat unlikely that Ruby knows much, if anything, about Sam being Lucifer’s vessel. So any thanks, any repayment she sees Lucifer giving Sam has more to do with Sam opening the cage (and possibly with him being the Boy King) than it does with Sam being his vessel. Which means that those rewards? Ruby’s going to get them too. So not only has Ruby moved up in the demon hierarchy, she’s expecting to be rewarded by Lucifer himself.
And what’s more, I think, Ruby’s expecting to be right there alongside Sam. She talks about how he’s “angry right now” and how “it’s hard to see it now”; the entire track of her conversation at this point indicates that Sam will, at some point in the future, come to see that what she did was really for the best and that this is how things are supposed to be.
Because Ruby really did care for Sam. She’s trying to get through to him here, because she cares. When Sam calls her a bitch, she looks hurt. When he tries to attack her, and she explains that he used up all his MP on Lilith, there’s concern in her voice. When Dean bursts into the room, she doesn’t attack him, simply stands up (in front of Sam, in a protective position) and tells him “you’re too late.” Why? For the same reason she’s never been as antagonistic as she could’ve been towards Dean— because she cares for Sam and Sam cares for Dean (and, OK, yes, because pissing off Dean too much would alienate Sam and that would cause her plans to backfire but at this point that doesn’t much matter).
At one point, Ruby talks about how she still remembers being human, and that’s why she’s helping Sam. I don’t know how true that is, but I think in some ways she’s the demon (especially in the first five seasons) that is the most human, and that really comes out here.
So, yeah, this is her being revealed as a villain and, in many ways, the villain that’s been more immediately responsible for what’s been going on in S3 and S4 than Lilith. But this is also revealing so much more of her character.
So, yeah, Ruby is the best of those sons of bitches. Ruby is awesome. Props to you, Ruby.