Rather than use a 'translation" which is merely a translator trying to make things palatable to people who don't speak Hebrew, let us look at the Masoretic Text, which is the one that has the oldest manuscripts, including Books like Isaiah being the same in the Dead Sea scrolls as the MT. (Written well before the time of Christ!)
Gen. 6;4 starts with the word הנפלים, which transliterated means "the nephilim." noun, masculine plural, from the root verb נפל, which means "to fall". Brown-Driver -Briggs translates it as "giants" and of course it is the same in Numbers 13:33. The notes say that the etymology is "very dubious."
So are they "fallen ones" or "giants"? I think it is safe to say, we will never know in this life. As for figuring in the end times, well, LOL.