Nephilim are a mixed breed of angel and "demon." They are, by definition, the Fallen Angels. They believe they are gods over others. There are ways to know whether or not you are one. One sign is if you get a soul dive by one experienced in it.
A lot of Humans have an ancient lineage of Annunaki DNA within. These are the ones who built the Great Pyramids, and interbred with Humans. Almost every Human is a hybrid being. We are a mixed breed... some of us are Pleiadian, Greys, etc, etc... everyone seems to want a stake on Earth. Some are conquerers, some are benevolent. The Nephalem are conquerers.