Okay in light of these tags I just dumped under This post I do actually wanna talk a bit more about the parallels/similarities between c!Dream and Darth Vader and the endings of SW and Dsmp
I wanna talk more specifically about how both c!Dream's and Vader's main downfall was from being attached to a part of their life they weren't able to let go.
In Anakin(Darth Vader)'s case it was from the possessive attachment to Padme, which the fear of losing Padme that was born from this attachment was the driving factor for Anakin's complete downfall.
And that was what the "no attachments" rule in the jedi Code was trying to prevent. A lot of people interpret that as a rule against love, even though the Jedi's main defining trait is compassion which is literally a core part of love. The "no attachments" rule was about accepting the fact that change -- be it in people, a place, society, whatever -- is inevidable and your love for something or someone shouldn't trap them in a specific version of being, but rather be willing to give them the space to breath and change and change alongside them.
Anakin's problem was that at some point he started being attached to Padme not really as a person but a concept and something he owns. When he got the force vision of Padme dying in childbirth, his attachment(and manipulation from Palpatine) made him turn to the Dark Side in an extreme attempt at preventing losing her, but he ended up getting lost in it and that lead to him being the cause of not only destroying his own life but also pretty much the entire galaxy's.
c!Dream's problem was being attached to an idealised version of the past and that attachment making him unable to accept that it had passed, that that era had ended the moment L'Manberg was created, leading to him taking extreme measures in an attempt to try reestablish that idealised past and in the process hurting others, hurting himself and destroying the last of what was left of that part of his life, doing the complete opposite of what he was trying to do.
This is where c!Dream's and Anakin's similarities are the clearest. In their unwillingness to let go of their respective attachments(Padme and the Early Days of the server) they selfishly ended up destroying everything good about their lives and hurting not only themselves but a lot of other people. They both did a lot of terrible, terrible things.
But they both wanted to be better, for things to be better, deep inside.
In their downward spirals of self-destruction, both had accepted that they themselves are evil and rotten and corrupted and even played into it. And yes, there is the difference of Anakin having lost everything at the start of his spiral and staying by Palpatine's side because he believed he had nothing else, nothing to lose, meanwhile c!Dream was still holding on to his vision of "One big happy family" for most of the story, believing that it could still be achived, and trying to use the "c!dream the big bad villain" persona as a tool to achive that. But the point of them believing that their way of self-destructing and violence and extremes was the only way for them to get what they want, the only way for them to be, is still there.
And that's how we get to their respective finale's.
In SW, Luke was -- understandably -- hostile towards Vader, but after finding out that Vader is his father, Luke started seeing him from a new light and believed that there was still goodness in him, going as far as literally giving himself up to the Empire in hopes of talking to him and making him understand that it doesn't have to be this way. It didn't work at first, Vader didn't believe him, but it did plant the seed of doubt in his mind and over the course of "The Return of The Jedi" that doubt and the realisation that it's not too late to fix something grows more and more until the moment where he does the right thing and kills Palpatine.
The discduo finale had a similar but also very different pattern. It began in the similar way of c!Tommy hating and being hostile towards c!Dream, but after dying and literally seeing things from c!Dream's perspective, he begins to understand c!Dream and realise that he himself was also part of the problem, that he himself also had part in continuing the cycle of violence. After realising that for himself first, he immediately tries to make c!dream understand that, to make him understand that it does not have to be this way, that they can stop it here and now. c!Dream, similarly to Vader, at first doesn't believe him, argues with him, but eventually starts to truly listen and consider the possibility that maybe it isn't too late, maybe there's still a way to fix this.
But here comes the main difference of both of these character finales; Vader got to do something, to make it not be too late, c!Dream didn't. Vader's saving grace was Luke seeing Vader's humanity before it was too late, c!Dream's(and the rest of the smp's) doom was c!Tommy seeing c!Dream's humanity after it was too late.
But c!Dream still got to consider, to realise that there was a way to stop, to be better, and that's what matters, even if he didn't get to do anything about it.
I do also want to bring up the parallel that in both finale's, along "the hero" and "the villain" both also had a third character -- the one in the way of the Villain's self-realisation, in the form of Palpatine and c!Punz respectively. Now I'm NOT saying that c!Punz was a Palpatine level of manipulative force of pure evil BECAUSE HE VERY MUCH WAS NOT, however the role that both of them had in enabling Vader's and c!Dream's self-destructions and holding them back from realising that they don't have to continue being like this is undeniable.
In the end, Vader and c!Dream wanting to change -- and in Vader's case actually doing something for that change -- doesn't excuse all the pain and hurt they caused, all the selfish and terrible things they did. But the point of "even the worst person you know is capable of change" that both of these finale's have is the thing that matters. Yeah, sometimes it's too late for that, sometimes it's not, but in either case, the fact that even the worst of the worst is capable of taking the hand offered, of being better, is important to recognise.