After Justin heard Vincent's suggestion, he immediately became interested.
To be able to establish relations with the humans was definitely a great thing for the vampires. Not only were the humans powerful, but the vampires would also be able to maintain a friendly relationship with Vincent. This was equivalent to giving the vampires a powerful friend.
If it was any other time, Justin would have agreed to Vincent's suggestion without even thinking it through. However, as Vincent had also proposed to obtain the secret of the blood pool, Justin felt a little awkward and did not know how to respond.
