Dreams about a demon

As a child, I had consistent nightmares about a demonic character who would offer me the power to fly but would demand blood from me as payment. These nightmares began at age 6 and continued until approximately age 12. I had several recurring nightmares again from age 19 until age 23, with essentially the same form: this demonic character would appear in my dreams and demand blood. These dreams became more violent and graphic, with the demon showing me his name written in blood on my thighs, and demanding that I etch his name on my body with a blade that he would offer in my dreams. Obviously, these nightmare have been deeply disturbing to me. I moved to Israel at age 28 (6 years ago). Until last night, I had not had any dreams with this character since moving to Israel. Last night, I had a similar dream, but the demon appeared as a dead and bleeding (but somehow still alive) character trying to drown me in dark water. I want to emphasize that I don't believe in demons (or angels). I'm not a spiritual person, and I'm only minimally religious (Jewish). But I'm wondering if anyone can speak to the potential significance of these dreams (if there is any). What do Christian teachings have to say about demons?