DNA
The truth was Quinn didn't need the quest notification to tell what was in front of him because he already knew based on the strange feeling and looked at what was exactly in front of him. Somehow, someway, the person in front of him had either gotten their hands on Werewolf DNA or was a werewolf themselves.
When fighting against Graham, during his transformation into a celestial, Quinn had heard the other leaders claim that Graham somehow had been mixed in with Werewolf's DNA. According to what Quinn had learnt from Logan, it was most likely an accident due to the information and different DNA used when Jim had created the Dalki in the first place.
However, seeing the person in front of him, and not only their features but the fact the quest claimed it was an ancient enemy of the vampires, Quinn knew why he was getting the same feeling, and the claw mark confirmed it.