Elysia
You do a quick read of the future... No vampires in the immediate vicinity.
The big person from the vision enters the room. He (or she?) is muscular and on closer inspection has a pair of modest sized horns on its head. The first resident makes a gesture towards the big resident, and the big resident sits down on a carpet on the floor.
"An offworld Witch hunter are you? I got a bad feeling about this. Alright. Fine. I'll go over the basics of what you need to know."
"There are three Kings on this planet. Skeeter D. of the Rappas, Melatana of the Selkies, and Amanmet of the Jeli. The kings are the biggest and baddest of the vampires, and they have unimaginable powers. While the power of these vampires is insurmountable, they almost never leave their lairs. They are known for following a set of archaic rules, the details of which we don't fully understand. You won't have to deal with them directly unless you do a lot of damage but if you do there is nothing that will save you."
"There is also at least one Lord. The lords tend to be rather enigmatic. As far as I can tell, they just do whatever they want and go wherever they want to go. They say that if you mess with one of the lords, every vampire around will go after you regardless of their clan. No idea why."
"Beneath the Kings are the Dukes. Each duke controls a specific territory and carries out the will of the Kings. They are powerful in their own right, and their minions are never far. I don't advise going after the Dukes either, they avoid a fair fight whenever they can and they are very good at it."
"Beneath the Lords are Knights. The lord and knight vampires are of a different stock than the others. I've only met one of these guys and she just gather mushrooms near my house for reasons I cannot possibly understand. I'm not sure what to make of them."
"Beneath the Dukes are Mosquitoes. This is the weakest classification of vampire and the one you will most often encounter. They are still stronger than any normal person ought to be though."
"And a special mention should go out to the Unmarked vampires. Its a subcategory of Mosquito that drank the blood of one of the Dukes without their permission. You can identify them by the lack of fang marks on their neck. Only the Kings, Lords and Dukes can make new vampires so the fang marks are difficult to fake. The kings themselves have made it very clear that they do not consider the unmarked worthy of their order, so if you see an Unmarked vampire you can kill it without fear of retribution. And if you think you can then you should. They are by far the most likely kind to kill someone in a predatory attack."