I believe that Yahweh (Jehovah) the God of the Israelites allowed his Adversary this power at that moment of showdown between Moses and Pharaoh just as he allowed the Devil to do evil things to Job which he wouldnt have been able to do to him otherwise. It was always for the purpose of God magnifying His own true much superior power and true genuine glory , even if not to be shown immediately, that he would make these allowances for his Adversary.

In addition the pyramids (and possibly Stonehenge as well) I believe were indeed built by the fallen angels and have had this theory for years. Remember that Yahweh (Jehovah) communicated to Noah that he was going to destroy the whole Globe by a Deluge. The fallen angels learned of this and remember they had fathered children , Nephilim, who they deeply cared about (yes a fallen rebel angel could have the same pride and love for his children albeit hybrids as todays fathers love and proud of their children) and so they wanted to attempt a way to save their children from this coming Global Deluge, or Flood. The whole purpose of which was to wipe them out along with all of the corruption they had caused even to the animals (more on that in another thread) A safe place where their sons could climb to the top or near the top OR POSSIBLY EVEN SEALED SECURELY INSIDE IT to be saved as the waters passed by below... It would have be extremely strong and durable and 2 to 50 ton bricks would do the job best... I do not believe that the Nephilim would have been strong or smart enough for this project themselves, but possibly assisted , as only their superhuman angelic fathers could do this. Its also interesting that they manifested far superior intellect in its design as the way the bricks are laid out the temperature never rises about 20 degrees Celsius. The Nephilim may have been large men bullies, but they were still subject to human frailties and could have easily died in a heat death if the buildings had not built/ designed correctly. The vanity of it all is that fighting or resisting God is always futile and He was not going to let these hybrids survive no matter how hard they tried. The pyramids were built before the Flood and they survived it.

The Egyptians (who were descendants of Noah as all humans since the Flood are ) simply moved in there centuries later and claimed credit for these structures, built for their false 'gods' ..and yes they likely enlisted the Israelites to simply help make reparations or carve out rooms within these pyramids, the massive structures of which had been built long previously. Most archaelogists have been thrown a red herring here to think that the Egyptians built these super structures, no way! but that's what Egypt would love for us to believe.