Varien's sincerity
Sam is radiating killing intent for the first time he came here.
He looked at Arav as if he is looking at the lowest grade of the pests but the most annoying of them all as if he wouldn't be able to rest until he kills it completely.
The reason for such a huge reaction is the cowardly method that was used.
If Arav came at him directly to kill him, he would have not cared much. He would have killed him, but that was just playing tit for tat.
But he used such a method that was completely uncalled for. And the worst part is, he doesn't even know who this guy is. He never met him, didn't have any contact or encounter.
He could guess some things but those are just guesses at the end of the day.
Sam looked at him as his body slowly regenerated. Even without the light element, the vampire body itself has a high regeneration. Even though it is not as fast as healing himself, it still works.