: Akhenaten was promoted to co-regent along with Amenhotep III. S/he was only 20 years old, meaning that his/her ascendancy was always the plan. And what was that plan?
The attempt to discredit Sarah & Abraham, by blaming them for the plague, did as much damage to the Amunists as it did to the Princess & the Brahmin. The plague is typically spread by fleas. The ancients didn't figure that out, and rather concluded that it was being spread just by the wind. Since Amun was the god of the wind, either Amun had turned on the Egyptians, or at the very least, the wind had been usurped by a more powerful god. The result was a loss of confidence in Amun.
All other factors being the same, this would have sent the pendulum swinging toward the Ra cult, promoting the priests in Memphis to dominance. Since the state religion was the worship of Amun-Ra, the Ra priests were already well represented in the government, including the administration of the delta, and they were well positioned to take over the rest of the country. But this was the last thing that the Amun priests in Thebes wanted. So they used their influence — while they still had some — to promote their own alternative to Amun that didn't favor Ra. To attract the swinging pendulum, they focused on Sun worship, starting with Atum (i.e., the other Sun god popular in Memphis). Then, to keep the Atum priests out of it, Sun worship was redefined, to be different enough that the existing priests couldn't claim expertise in it. Thus the Aten was conceived, as an indescribable creator god, the source of all life on Earth, but which did not reduce just to the powers of Atum, or Ra for that matter. The champion of this new religion would be the pharaoh, who would designate himself as the sole instance of the Aten. So they didn't have to create a whole new priesthood, and populate it with people loyal to them — they just needed for the pharaoh to be on their side, running the new religion the way the Amun priests wanted it run (i.e., into the ground). In other words, if the dominant religion wasn't going to be Amunism, it was going to be an alternative concocted and controlled by the Amunists, and it wasn't going to last long.
Amenhotep III's heir apparent was Prince Thutmose, but as the high priest of Memphis, he was already a recognized expert in the Ra cult. A better candidate to lead Atenism was his younger brother (or sister) Akhenaten, who had not been groomed for any particular political position. So Akhenaten was promoted to co-regent.
Meanwhile, Isaac turned 20 years old, and having completed his education, began his ministry, which would ultimately lay the foundation for the Druze, who believe in repeated reincarnations, ultimately culminating in the soul uniting with the Cosmic Mind. The Egyptian disdain for such Hindu beliefs resulted in the Druze being pressed into Syria, while those staying in Canaan went underground. And though Abraham was called a prophet in the Torah, and Judaism is an Abrahamic faith, there is nothing left of his prophecy — his only surviving contribution to Judaism was that he accepted a title in Canaan in return for declaring his loyalty to Egypt by circumcising his sons, which isn't even the beginning of a religion.
Figure 1. Standardized blocks (27 × 27 × 54 cm) used to build Akhenaten's temple at Karnak.
: Amenhotep III (aged 58) passed away, and Akhenaten (aged 28) assumed sole regency. Akhenaten immediately began building temples to the Aten. Tellingly, the first temple, which was at Karnak, was done with small stones, not large ones.1 (See 2.) Large stones contributed to a sense of permanence, while small stones were more temporary — cheaper to quarry and easier to fit together, but easier to tear down as well. If the intent was to temporarily let the pendulum swing toward Atenism, planning for it to swing back shortly thereafter, this construction style makes sense.
: Akhenaten moved the capital to Amarna. There was more to this than just getting a fresh start in a new city, away from the politics in Thebes and in Memphis — Amarna doubled as a leper colony. In other words, Akhenaten did the same thing to the followers of Atenism that his father had done to the Brahmins — he tried to discredit them by associating their names with serious diseases.
: Among the royalty & nobility at Amarna was Ramose, former junior vizier to Amenhotep III, tutor to Akhenaten, mayor of Thebes, and now senior vizier to Akhenaten, and general of the army. Ramose's family was from Memphis, where his father was the mayor. He seemed to be an early & ardent supporter of the changes during this time, since his tomb in Thebes is the earliest done in the Amarna style. But he got on the bad side of Akhenaten by killing the "Younger Lady" (sister of Akhenaten and mother of Tutankhamun) for mistreating the slaves at Amarna. Fleeing for his life, Ramose moved to Midian (across from the Red Sea). There he was taken in by Isaac, son of Abraham, and founder of the Druze. Ramose married Isaac's daughter Zipporah, who bore him two sons, Gershom and Eliezar.
: Akhenaten (aged 44) died, to be succeeded by Nefertiti, who invited Ramose to return to Egypt and accept the position of co-regent, to be recorded in the kings list as Rathose. He continued in this position for 6 years, which included 2 years into the reign of the boy-king Tutankhamun. The capital remained at Amarna, and Atenism remained the state religion.
: Jacob (aged 18) was told to move to Mitanni. Perhaps this was preparation for ceding territory to the Atenists a little later. If Isaac had divided Canaan into southern & northern provinces, to be administered by his twin sons Esau & Jacob, where Esau got the prime real estate nearer Egypt, and Jacob got the lawless frontier, perhaps it would be easier to send Jacob back to Mitanni, leaving the frontier ungoverned for a few years, before handing it over to the Atenist priests.
: Horemheb was promoted to senior vizier and heir apparent, who convinced Tutankhamun to move the capital back to Thebes, reinstating the powers of the Amun priesthood. Amarna was abandoned, and Ramose (aged 53), along with 70 of the high priests of Atenism, were exiled to Moab. Ramose changed his name to Otni'el in acknowledgement of his new station in life — formerly he was the co-ruler of Egypt, but now, he was just a leader of what was left of the Aten cult, now in exile on the border with Canaan. Also exiled were Ramose's sister Miriam, and Prince Thutmose, who was remembered as Aaron (meaning "exalted"). As high priest of Memphis, Aaron had begun his ministry before Ramose, and politically, was the senior of the two. His offspring would also be possible heirs to the throne, if the political winds had changed. Thus he was the founder of the kohanim. But Horemheb favored Ramose as the spiritual leader of the exiles.
The rest of the 50,000 inhabitants of Amarna were relocated to Avaris, where the more arable land afforded sustenance without government subsidies.