In The Finished Mystery, published in 1917, they said that Armageddon would really break loose in 1918 with the destruction of "Christendom" and all the church members and by 1920 all kingdoms of the earth would pass away.  In 1918 the "little flock" would pass beyond the veil and 1921 would be the last year to make it to heaven and would see the death of all in the "great multitude" class.  The Finished Mystery claimed, as did other Watchtower material in 1917, that they were directed and supervised by the spirit of the dead "Pastor" Russell and others of the deceased "anointed" class.  This is necromancy, or communicating with the dead, which the Society has called spiritism and demonism.
The next year, 1918, was claimed by Rutherford to be the year when the Holy Spirit was removed from the remnant and angels began teaching them the truth. Did the "light get brighter"? No. This new source of spiritual enlightenment was no better. In was in 1918 that Rutherford began to deliver his lecture, "Millions Now Living Will Never Die" which he believed was the "gospel of the kingdom" that was to be preached to all the world for a witness and then the end was to come -- in 1925. Given that Rutherford claimed angels were responsible for everything he published, the Apostle Paul's words to the churches in Galatia about other gospels from angels are relevant. (Galatians 1:6-9)
Rutherford preached a gospel other than the one Paul preached. Not only that, the "Millions" gospel and prophecy failed. The kingdom was not set-up in 1925 with the resurrection of Abraham and others. Bald heads, false teeth, and other things prophesied to either end or take place in 1925 and shortly thereafter, did not occur. The angels, if responsible for this, were lying spirits by definition.
The Golden Age printed two news items that stated that "demons" had been recently telling the spiritist Conan Doyle that 1925 was to witness events paving the way for the Millennium. They said that demons apparently have advance warning of what is about to happen, thus they apparently believed these particular demons were "honest". Rutherford said he made an "ass" of himself over the failure of his 1925 prophecy.  If his claims were true that the information he published concerning 1925 came from angels, the angels made an "ass" of Rutherford which further identifies the nature of these angels. They are the same or similar to the "demons" the Society said communicated the same message to Conan Doyle through mediums.
Despite this failure, and being made an "ass" of by these angels, Rutherford continued to listen to them and publish what they transmitted into his mind. This included further false prophecies such as his WWII prophecy of Armageddon. I don't think I need to labor this point to death. The evidence is clear. If Rutherford was publishing material that was transmitted into his mind by angels, the "angels" were demons.
Excerpts from: http://www.premier1.net/~raines/medium.html
The Spirit World Guided Rutherford
Was Rutherford a Spirit Medium?
Doctrines of Demons
Twaddle and Malarkey