Tw: Discussions of child grooming and abuse, please be mindful in the notes
I've been thinking a lot about why I like Ventus as an aro person and why a lot of Ventus fans are on the aroace spectrum... I think it's because I love how Ventus's abuse and objectification are a criticism of romance tropes glorified in fiction, specifically Disney's ideas of a prince saving a princess and "true love."
Ventus is very well loved by the people around him, some in healthy ways, but many people, specifically the ones steeped in darkness, take it too far.
People in the throes of darkness feel like they need him and his light, and they break all their rules of self to adore him. They think of him constantly and center their entire lives around him, but in the process they always destroy everything around him, everything Ventus the person cares for, for the sake of being the only one to have his light, be it the light of Kingdom Hearts, the warmth of emotion, or the end to their loneliness. They want to be Ventus's one true love at the cost of cutting out all his other loved ones, and they want love so mutual and unbreakable they would rather Ven a sleeping corpse than a talking person, a key in a lock, even though they originally loved him for who he was-- Xehanort writes in his diary about bring compelled to take Ventus somewhere calm for him to die, and yet he still forced Ven into the role of the X blade, sitting him on the throne as queen.
Their "love" is love that is all focused on one person, only that person forever, willing to hurt and sacrifice for that person's sake, hurt themselves and others, all just so they can be near that warmth all the time.
I think the fact that these people are characterized as pure anger negativity and trauma (Vanitas) or sinister old men (Xehanort and Luxu) really serves to destroy any sort of facade of romance and pleasantness this toxic love could have held. The pure fact that none of these people are people Ventus could healthily love for as long as they want to love him due to power imbalances and age differences speaks volumes, forcing the audience to disregard any romance the obsession might portray itself as and see it as Ventus sees it-- someone more powerful, more angry, more dangerous than him, who has no right to do this to him, even if it is love.
Youth and beauty and charm would mask the true nature of the "prince" role in Ventus's story. The concept of a true love's kiss is (very symbolically) a bad thing that would seem sweet and tender if it wasn't a cruel prince of gore and bare viscera opening Ventus's coffin to wake him. Despite how "becoming one" and accepting Vanitas's open hand would give a normal princess a happy ending, Vanitas and Ventus becoming one would end the world, and Vanitas often uses phrasing normally reserved for marriage proposals when demanding Ventus join with him, a final end to a story Ventus desparately needs to keep going. They were "made for each other", but that doesn't mean Ventus chose that-- fate did. That red string did. Ventus's autonomy was taken and then only given back via giving into the demands of someone who only wants a princess.
It's the same with Xehanort-- there was love there, I have no doubt about that and that Xehanort cared for Ventus. But while the love was genuine, Ventus was still given a role he didn't want by a man who manipulated him into the most moldable version of himself, nearly killed him, separated him from his family, murdered his father, all in the name of entering the castle only Ventus had the key to. Xehanort positions Ventus as a queen by his side, but what value do Ventus's feelings even have to him if they're not complete adoration, a perpetual willingness to obey and go along with the flow of Xehanort's plans? You can find someone endlessly wonderful and still not consider them a person. Ventus is dearly beloved, but that doesn't mean the longs he cares about are considered in the hearts of those who desire him.
I think the princesses Ventus is compared to encapsulate this idea well. Snow white and Aurora are only allowed up wake if they promise themselves to someone forever. All because someone wanted them to be an object of victory. I think the lyrics to this song in Snow White feel more foreboding when applied to Ventus... Forever is true love, and those who see themselves as his fated person want him to be forever.
His friends are different. Aqua and Terra learn over the course of BBS that the more they consider Ventus as a person, the more they get closer to answers. Likewise, Ventus isn't woken up by true love in any sleep-- it's Sora, someone who loves him not because of fate or desire, but because Sora purely wants Ventus to be safe. Empathy and autonomy and being loved without demands are what truly saves Ventus.
Tldr I think the way the tropes of Disney romance are warped and made bare by making the prince charming characters grotesque obsessive monsters who don't care for Ven's autonomy beyond possessing him is. Really good