There are varying ideas of what The Watchers are, but the consensus is that they were always bad or evil. In certain traditions of Italian witchcraft, they have another name for the Watchers, "Grigori." Supposedly, they are the portals between the physical world and the non-physical realm. The fact that The Watchers have been mentioned so many times in the Bible gives it a lot of weight. However, the Bible's contents should not be taken literally. It would be best to think of these fallen angels as symbolical to something in our real world. In Jewish folklore, angels were often cited. They were described as very big humans who do not sleep and are constantly silent. The watchers are cited either as good or evil, but majority of the tales were on being evil.

The offspring of these fallen angels are called Nephilim, and they were mentioned in the Book of Numbers (13:32-34). Purportedly, Goliath who fell because of David was another descendant of this race.

Yes, they are evil definitely. Read the Book of Enoch. Supposedly, their mission was just to watch us mankind, but lust got the better of them and they defected. They engaged in sex with humans, and to make matters worse, the children produced were worse. Called Nephilim, these were giants who wreaked havoc on earth. I think this topic is also mentioned in the Genesis of the Bible. In some modern cultures, they have their own variations or interpretations on this topic. In the book The Powers of Evil (by Richard Cavendish), it was suggested that these giants were Greek mythology's Titans. Given their descriptions in different sources, it cannot be denied that The Watchers are fallen angels, those who switched side from good to evil because of lust and temptation.

Well, when we say "fallen," it would be best to consider the differences. The Watchers and Satan are both fallen angels, but their capabilities for evil differ. Of course, it would not be impossible to assume that some of The Watchers could now be in Satan's league. I believe that there would always be exceptions. There must have been a handful who remained loyal and good. Some theologists actually consider The Watchers as beings between angels and mankind. For all we know, they could be symbolism of the purgatory. Cardinal Newman believe that angels belong to the neutral plane, neither evil nor good. This is actually a safe assumption that I could believe in. If we truly believe that God is all-merciful, then surely, He would differentiate between a "partially fallen" angel and a "totally fallen."