The Marvel Cinematic Universe spent its first three phases in a fairly streamlined continuity where nearly every event was either reconciled or brought up in later installments. However, with Phase Four, the franchise has exploded into multiple directions thanks to the multiverse. But with the birth, or rebirth, of more realities, the larger threat of Kang the Conqueror and what he could do to the timestream is now a dangerous reality that must be acknowledged. But has his presence already influenced the history of the MCU?
As revealed in a breakdown video for Episode 3 of Moon Knight, a thug that Marc Spector is shown fighting has a symbol on the back of his jacket that serves as a subtle callback to Kang the Conqueror's Rama-Tut identity. In the comics, Rama-Tut was a pharaoh who ruled and conquered but was actually Kang living out a new identity. However, in the MCU's past, Rama-Tut was never mentioned, even though history has played a significant role in the franchise thus far.
With this subtle realization, Kang and his variants likely have already started their temporal warpath of conquering various realities. However, with the MCU timeline, things may not be that simple. As a result, one possible explanation for why he would appear as Rama-Tut first could be because he needed to better align his pawns before making a larger move in the timeline. This could mean clearing the board of any deities or building up a deep connection with his followers that would last until the modern-day, so he'd have an army willing to fight across the world.
Kang's potential temporal tampering could also be the reason why the prime timeline of the MCU has grown so much in power. In terms of magic, witchcraft and the supernatural have taken on a larger prominence when before, sorcery appeared as the main means to use the world's energies for magic. There's also the inclusion of gods like Khonshu, which may have been introduced by an even earlier version of Kang, who manipulated the origins of reality enough to introduce gods to a timeline that never officially had any. There's also the larger presence of alien technology and the arrival of the Eternals and Celestials that have taken an interest in Earth coincidentally around this time. But why create a planet so strong he may be unable to conquer it?
Kang has always been hundreds of steps ahead of his opponent in the comics. While it may seem foolish to create powerful characters like Moon Knight, the Eternals and Scarlet Witch, his main plan could be to soften Earth up with this otherworldly conflict. With the fabric of reality strained thanks to events like Spider-Man: No Way Home or the actions of Khonshu manipulating the stars, the world is fractured just enough for Kang to reappear, call on his army and walk across the world as its new ruler. But the scariest aspect of this plan is how no matter what it seems like, it's part of a larger plan; it could all be a part of Kang's plan, which would make him the most powerful being in the history he has edited.
In the past, Doctor Strange could see possible realities in the fight against Thanos to see which one would be the winning reality. But now, with Kang in control, anything Strange would see, if he could, would be manipulated enough that Kang would always win. But, as Loki showed in its season finale, Kang is one step ahead of reality, and before one could think to stop him, he would have already won. Therefore, everything that's happened or is happening now in the MCU could all be a part of his larger, more nefarious plan to have won before the battle even started.