Revelation 12:7-9 And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels,
8 And prevailed not; neither was their place found any more in heaven.
9 And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.
Demonic activity:
John sees war in heaven in which the devil with his angels are cast onto the earth and then declares a woe to the inhabitants of earth because of the spiritual forces now consigned to earth. The tribulation period is not only a time when the wickedness of man is released by the withdrawn hindrance of the Holy Spirit but there will also be demonic activity probably beyond any that has happened on earth previously. There has always been demonic activity on earth after the fall of the devil but during the tribulation this will increase exponentially.
Other times of activity:
When God sent Moses into Egypt to bring His people out of bondage there was a display of power supernatural demonic activity. When Moses threw his staff on the ground and it became a snake the magicians did the same. Then the waters were turned to blood and the magicians did the same, then frogs were brought up onto land and in houses and the magicians did the same. But when the dust became lice the magicians could not duplicate this miracle.
When Jesus walked earth there seemed to be a goodly number of people who were affected by demonic activity. The maniac of Gadara who was possessed of a legion of demons, the young boy possessed from a child. Mary Magdalene possessed of seven demons and numbers of other who were deaf and dumb by reason of demon affliction.
During the tribulation there will be demonic activity:
The withdrawn influence of the Holy Spirit after the removal of the church will open the gates to more and stronger demon activity. The anti-Christ will probably be a devil possessed person as well may be those who rule with him. In Dan 2:43 it speaks of the ten kings as represented by the ten toes of iron and clay mixed together and saying that as iron and clay do not mix together to be strong so the ten kings mingling with the seed of men will not be strong. Also in Rev 9:1-5 it speaks a swarm of locusts coming out of the pit that cause pain to men but not death.
Computer people:
In recent years there has been technology proposed and attempted that would infuse the thoughts of a person into a computer and then at death that essence of that person would be transferred into a droid – humanoid-type creature. Experiments with 100 people has shown that they can communicate with computers by thinking certain words and the idea is to eventually create a link between a person and computers and even the internet information so a person could think and research things and have instant access to answers. Could some of this technology be used in the anti-Christ and a fatal wound and back to life experience? There is much we do not know but research in these areas and advances surly point to the possibility.