So how exactly to passive and active classes differ. Like all I ever see is "Yep a Mage actively understands their aspect and a seer passively understands their aspect." Like yeah I get that, but nobody ever goes into real detail on what passive and active pairs really mean. (Sorry if you already have a post that explains it all)

I did do a big talk about it a while ago, and here the dichotomy, as @revolutionaryduelist has talked about in the past, comes from a Selfishness vs Selflessness point of view.

See, the idea is that we are given a reduced view of God Tier powers by Calliope, she mentions “Exploit” vs “Allow”, but she also mentions it’s by no means a rule set in stone and that it’s more complex than that. So taking it from the actual Canon, you have the Lord and the Muse, the most Active and most Passive Classes respectively. If they truly are the most Active and the most Passive, it would make sense that Lords would only ‘Exploit’ directly, and Muses would only ‘Allow’ passively- Yet, Lord English does little to Time itself, the Alpha Timeline just so happens to fall in his favor, there’s a sequence of events that must bring him into being, and that allows for him to exist and Destroy everything he wants. His control over the Timeline is extremely passive. On the other hand, Alt Callie physically and very directly takes control of the Space around her and collapses it and herself into a Black Hole to tear the entirety of Paradox Space, an action that seems incredibly active. So this means there must be something more to Activeness vs Passiveness.

And that something, as far as we’re theorizing here, is that Lord English’ control of the Timeline benefits him and only him, and Calliope suffers an eternity of Isolation to fulfill a task that will bring down Lord English and tear down the complex time loop that is Paradox Space, for the benefit of the characters of the story. Lord English is extremely Selfish, Calliope is extremely Selfless, and this is something we can see being shared across all of the characters in one way or another.

John, a Heir, Passive, is all about his Friends and helping those he loves, to the point of constantly refusing the thought of Leadership. Karkat, for all his leader banter, is actually a softie that loves his friends and is only trying to push the team through. Roxy even specifically mentions how she hates her selflessness at one point. Dave and Rose both argue about wanting to go sacrifice themselves in each other’s places, and eventually sacrifice the two of them to blow up the Tumor. On the other hand you have Jane, who suffers incredibly when she’s being repressed by Jake’s obliviousness and relationship issues and not allowing her to actually express and take care of herself. Dirk, who struggles with taking too much control and being too overbearing and centered on himself. Not to say that Passive Classes can’t be Selfish and Active Classes can’t be Selfless, but as you examine the path of each character, you start to find their ‘happiest’ times tie in to this Selfish vs Selfless division. And of course that doesn’t mean Selfish = Bad and Selfless = Good- Selfless can definitely be seen as the ‘Greater Good’ or ‘What’s good for someone evil’, as we see with Aranea and with Gamzee respectively, while Selfishness can just be being content with something else that isn’t the Big Quest To Save Paradox Space, as we see with Aradia, just wanting to live on and watch the Ending, but still interacting in a friendly manner with everyone around her.