Vampire (EntityClass, 4)
From Compile Worlds
Vampires are beings, usually described as evil, that find blood to be the tastiest thing in existence. They're usually portrayed with lots of strengths. Namely: super strength, super speed, ability to turn to a bat or mist, flight, mind control, immortality and other stuff. Not that their exclusive powers are the only things they can get. Remilia and Flandre's existence can tell you all the you need to know. It's because of this that they are called "The Lords of the Night".
They've got just as many weaknesses as they have strengths. Sunlight (Hence, why it's only "Lord of the Night), silver knives, flowing water, onions, crosses, broken holly branches, sardine heads, roasted beans... you name it.
If you know a series with a fantasy setting, expect a vampire or two to appear. They're EVERYWHERE... everywhere dark, anyway.