Nina (Jenny Wade) is a demon from hell who mostly takes the form of a hot young woman.
After seeing Ben take care of a bunny, Nina falls in love with Ben. She had made an effort to kill Sam. Being a Demon she has been on a quest to hunt down and kill off all of the Devil's offspring. When the boys first find out that Nina is dating Ben they tell him to break up with her, as it may just be an act and a way to get to Sam.
When he did she almost turned into her demon form but she stopped and cried acid tears. Then after Ben spoke to Sam, he got back to together with Nina. She decorated her hide-out to look more home like for Ben and she has even took Ben flying. Nina even surprised Ben by going to Dove Hollow where the gang were, but she got eaten by the escaped soul, when Ben found out he took the vessel and captured the soul all by himself, which made the soul's caretaker mad and caused him to chase the boys with a shot gun, then Sam threw the vessel at the caretaker and Nina popped out and almost killed him, but Sam told her to stop.
Then thinking he was evil, she kissed him (Sam, not the caretaker), Nina is afraid God will smite Ben like he did her first love. After she meets Ben's Grandma, Nina and Ben break up. Then they got back together. After Ben and Sock burned down Nina's home, she moved in with the guys. Now Nina is in heat. She told Ben that demons go in heat just like animals. Nina and other demons killed Sam's half-brother Morgan.