Vampire Academy is already a world where almost every character is expected to sacrifice what they want for the sake of their duty to the Moroi. So how much would change if their literal souls were walking beside them, able to disagree with them, call them out, and express the feelings they're trying so hard to suppress?

Like... imagine Dimitri insisting he doesn't have feelings for Rose while his daemon (I think he'd have a wolf) is constantly curled up next to hers (I think she'd have a tiger) or openly seeking Rose out whenever Dimitri isn't looking. Maintaining the image of the perfectly disciplined guardian would be a lot harder when everyone can literally see your soul.

Or the implications of Strigoi.

What happens to a person's daemon when they're turned?

Do they become corrupted too? Do they disappear? Do they lose the ability to speak and become feral, like the severed daemons in His Dark Materials? Or are they left wandering the world with a broken bond while their human has become a monster?

Just imagine Rose finding Dimitri's daemon after his transformation. Instead of the daemon she remembers, she finds a feral animal that can't speak or even recognize her, lashing out whenever she tries to approach it. Or maybe it's not aggressive at all—just a wounded, terrified creature, completely broken by the corruption of the bond.

And then there's Spirit.

Imagine Rose's daemon changing as she's affected by Lissa's darkness. Instead of the corruption being invisible, everyone could literally see what Spirit's darkness was doing to her soul.

And the social implications would be fascinating too. Novices and guardians would absolutely be judged based on the forms their daemons settled into. Certain daemon forms would immediately be seen as "better" guardian material than others, regardless of how skilled the person actually was.