!SPOILER WARNING!
1. In the novel, the prince took a potion that changed his appearance, it was described that the man who bought Rishar was silver haired and was accompanied with a guard knight.
"A silver-haired man wearing a mask
quietly, yet with an unsettling aura,
approached. His silver hair, bathed in
clear moonlight, swayed diagonally.
A guard knight who had also covered his
face with a mask followed closely
behind him." - from the novel
2. The prince then brought Rishar in a bedroom and proceeded to somewhat kiss him and almost as if tried to s'a him. The guard knight was also in the same bedroom guarding the door.
"The man entered a bedroom. As if
telling him to follow, the guard pushed
Richard's back
First, I have to go back there
Richard looked down at his shackled
wrists and resolved.
By any means necessary, he had to find
a way to return to the slave market
Whether by knocking out his opponent or
running away.
Richard glanced furtively at the
silver-haired man who had bought him.
Can I take him down?
Though he couldn't tell who he was
because he wore a mask, he seemed to be
a considerable expert.
The guard knight protecting his side
was the same
Richard gritted his teeth inside his
mouth."
3. Rishar also bit the prince in the hand, and yelled at him that he hated men, going as far as to mention Kailus. The manhwa changed the words a bit...
"I!"
Even if he was like a lamb placed
before a predator, a madly thrashing
one is hard to catch.
"I hate men!"
He threw the pillow at the man with all
his might.
Although the pillow missed its mark, he
saw the hand reaching for him hesitate
for an instant.
Richard didn't miss that gap and
screamed hoarsely.
"Huh? Just because you're a high noble?
Just because you bought a slave?!"
"You perverted bastard! You might go
crazy at the sight of a man, but I feel
like vomiting just by brushing against
one!"
Richard was, quite frankly, straight.
It was headache enough that he had to
seduce Cailus, and now he was being
taken by some man he didn't even know.
"I like women! You son of a bitch, you
trash! A bastard like Cailus!"
-from the novel
4. Rishar didn’t immediately barged in the slave market half naked, he came in cloaked and hooded and it was described in the novel that as he killed the slave owners/sellers, the sword he wielded had a magical aura. When he freed Enoch, Enoch grabbed him and pulled down his hood.
"You."
A low voice resonated from behind
"?.."
Richard abruptly halted his steps.
He called me?
Though it was something he had repeated
dozens of times, Enoch had never once
called out to him first.
Truly, not even once
"..."
Half in doubt, half in suspicion,
Richard turned his head.
That was the moment
Swoosh-!
The robe hood covering his face was
grabbed by the other's hand and pulled
down.
Platinum hair scattered into the air-
Richard's revealed blue eyes widened
sharply.
"What are you-!"
"As I thought"
-from the novel

Awww, they changed some parts of it!