Here are three short passages from the Agni Yoga Teachings to pay attention to:
Satan is very anxious to make an end of the Earth, in order to concentrate his forces on the Subtle World, which cannot be destroyed in the same way as Earth. Thus the Proprietor of Earth through present treachery is betraying the Earth. He is a poor Proprietor in that he cultivated such a nature within himself. He causes Us double labor by keeping up the fires of chaos. (FW II, 187)
New planetary chemisms have an enormous significance. One may picture that the chemism of Saturn is attracting a certain type of being. Who knows what penalty is being prepared for those who serve Satan? You have long known the old legend about Satan. One must note that the fury of those who serve him already reaches the point of madness. Thus, for some the spot on Saturn is just a spot, but for others it is a confirmation of the old legend. Many manifestations are related to Armageddon. (FW II, 124)
Wherein lay the revolt of Lucifer?
He wishes to remain within the boundaries of the planet. And the legend of the Prince of the World is fairly true. He began to surround himself with spirits content with the earthly aura. In order to hold his followers he began to unfold before them the possibilities of earth, imitating—at times with skill—the counterposition of the opposing side. ...
Without him there would not be a definite boundary between the earth and the nearest spheres. Without him the difference between life on earth and on other spheres would be gradually effaced, permitting to incarnate spirits the movability of matter. But the Prince of the World, in opposition chains matter to the crust occupied by him. ...
Hence you shall have to depart to Saturn; for this, have you long been called Satan. (EC, pp 119-122)
FW II =
Fiery World II [1934]
EC =
On Eastern Crossroads [1930]
Not that I don't play devil's advocate too ... but I don't think the prince of darkness needs any help.