what exactly is it about desi that Vaughn finds so appealing? I love desi - but it just makes me wonder what is it about him that Vaughn finds so attractive? would desi ever be able to change Vaughn's opinion of him enough to escape from him?

Vaughn’s
fixation on Desi is due to the confluence of several independent factors,
rather than any one detail in particular. Some of those things we know from
Vaughn telling Desi about them, others are things Vaughn has left more or less
unexplained, and some are things even Vaughn isn’t consciously aware of.

The way
Vaughn’s explained it to Desi, his interest is due to the simple fact that he
finds Desi fascinating – a rarity for a psychopath who’s perpetually bored.
That in itself might have been enough to spark and sustain his obsession for a
while.

Vaughn’s
fascination derives primarily from the contrasts in Desi’s personality. From
their very first meeting during the job interview, Vaughn was intrigued that
this sweet, kind of shy young man had been ballsy enough to apply for a job he definitely
wasn’t qualified for, and then was able to passionately argue for why he
deserved it. And while Vaughn doesn’t care much about other people in general,
he does appreciate intelligence and competence, especially when they makes his
life easier. So when Desi proved to be an exemplary employee, that was another
plus.

Vaughn knew
instinctively that Desi was submissive by nature, and he liked that Desi never
sacrificed his intelligence or inner strength for that aspect of his
personality. (Which is something no sub should ever have to do, BTW, but many have unfortunately been taught
differently.) Vaughn enjoys the fantasy of having a sub who’s obedient and
submissive without being some kind of bland doormat.

Another
factor is that Desi’s background makes him particularly vulnerable to emotional
abuse and manipulation. A childhood like Desi’s – bouncing in and out of foster
care while his very young mother struggled with substance dependence – can make
its mark in a few different ways. In Desi’s case, he developed a desperation
for approval, affection, and love, especially from anyone he views as an
authority figure. He’s constantly striving for perfection, and he’s eager to
please in a way that puts him at risk for exploitation. Desi has spent his
whole life searching for a home where he feels safe and appreciated.

As Desi now
knows, Vaughn hired a PI to investigate him after their interview. That
comprehensive knowledge of Desi’s background, combined with what Vaughn had
observed personally, added up to a clear picture: Desi would be
extra-susceptible to manipulative techniques like gaslighting, guilt-baiting,
and emotional blackmail. Toss in severe financial need (due to Wanda’s cancer),
and Desi made a much more vulnerable target than most people would, which in
turn made him even more interesting to a predator like Vaughn.

One of the
factors that Vaughn isn’t so much consciously aware of is how much Desi
resembles his boarding school roommate. Vaughn knows there’s a physical
resemblance there – he told Desi as much during their drinking game – but he
isn’t aware of the depth to which that’s affected him.

Vaughn has
always thought of that roommate (whom he emotionally abused in much the same
way he’s doing to Desi now) as “the one who got away”. So there’s a part of him
that’s attempting to relive that former relationship by staking a claim on
Desi. I actually have some ideas about how Desi could meet the roommate in the
future!

As for Desi
escaping, the problem there is that now he knows the truth about who Vaughn is.
So even if Vaughn got bored with him, Vaughn couldn’t just let him walk away. I
think Desi knows this on some level and is terrified by the implications.