Derek and Casey's relationship: They both deny helping each other, but Derek will beat up anyone who calls Casey a whore, and Casey will put broken glass in girls food if they say something about Derek. But both say their relationship is purely physical.
All Vampires have the power to hear thoughts and send psychic signals to other vampires. If they're strong enough, their messages can cross continents.
Destructive punches. At passive, nothing odd, but when any body part applies force, the impact (punches, kicks) can be catastrophic.