Nephilim = Fallen Ones.
Genesis 6:4 The fallen ones were in the earth in those days, and even afterwards when sons of God come in unto daughters of men, and they have borne to them -- they are the heroes, who, from of old, are the men of name. (Gen. 6:4 YLT) Young's Literal
Nouns. The nouns mappāl, “what falls from the grain, refuse” (Am. 8:6), “flabby cheeks” (of Behemoth) (Job 41:15[23]); mappālâ, “heap of ruins” (Isa. 17:1), “ruin” (Isa. 23:13; 25:2); and mappeleṯ, “carcass” (that which has fallen: Jgs. 14:8), “fallen trunk” (Ezk. 31:13), or “fall, downfall” (Ezk. 26:15–18; 27:27; 31:16; 32:10; Prov. 29:16), fill out the picture without qualification. In the case of nēp̱el, however, we must examine its usage carefully. The noun probably does not refer to the process of birth (the falling of the newborn infant) or the falling of a miscarriage. Its meaning derives from the primary meaning of the qal: an entity whose necessary property is to fall, a casualty. The Nephilim (Gen. 6:4; Nu. 13:33) should be interpreted analogously. The noun seems to embody the notion, so characteristic of ancient Israel, that something gigantic, something exalted, must necessarily fall.1<a href="#_ftn1" name="_ftnref1" title="">9</a><a href="#_ftn2" name="_ftnref2" title=""><sup>[1]</sup></a>
Seebass, H. (1998). נָפַל. In G. J. Botterweck, H. Ringgren, & H.-J. Fabry (Eds.), & D. E. Green (Trans.), Theological Dictionary of the Old Testament (Revised Edition, Vol. 9, p. 497). William B. Eerdmans Publishing Company.
Satan has spread the strong delusion The Nephilim (Fallen Ones) were not his fallen angels who corrupted the earth after the Fall. The Watchers were sent to counteract their evil ministry on earth. Satan doesn't want anyone to connect the dots to the End Time, when Michael casts them out of heaven and they appear disguised as Extraterrestrial "Elohim" and deceive the earth once again.