"...just say it~"
Vincent: ...I...need your blood. Not-not all of it-just-just some-but-I...I wouldn't take it without your permission...
"and why would you need my blood?"
Vincent: ...Merfolk's blood is supposed to have healing properties...I-I can't say for sure but...I'm hoping...I'm hoping that it'd could be the cure.
"cure for??"
Vincent: ...Vampirism.
"and that isss?"
Vincent rolls his eyes
Vincent: Use context clues. It's the process of turning into a vampire...and I'm going to find a way to stop it.
"and why should I give you my blood?"
Vincent: It's not for me. It's for everyone else...think of the people who's lives could be saved with this cure. I...people should be able to have a choice...no one should be turned against their will. NEVER AGAIN.