Revelation 13:6

6  And he opened his mouth in blasphemy against God, to blaspheme his name, and his tabernacle, and them that dwell in heaven.

When Satan enters this man, the first thing this man does is speak blasphemy against God, his tabernacle and those that dwell in heaven. He will probably claim that all in heaven are alien impostors trying to control the earth. He probably will say that he is the real God and that he came with his angels to help mankind free themselves from enslavement to these hostile forces who now control heaven. Jesus said it would be like it was in the days of Noah at His coming .  In the days of Noah angels came down to earth and posed as gods (Genesis 6:2; Jude 1:6).