Tutankhamun did not directly succeed Akhenaten. There was at least one intermediate heir: Smenkhkare or Queen Neferneferuaten or perhaps both.
Tushratta, king of the Mitanni was not the enemy of Egypt. He spent most of his reign fighting the Hittites.
The Mitanni are shown as much darker than the Egyptians. This is unlikely: their kingdom was in what's now south-east Turkey, Northern Syria and Northern Iraq.
Ankhesenamun was Tutankhamun's half-sister, not full sister. (And would have been unrelated if Tutankhamun was not in fact the son of Akhenaten, as the drama has it.) And after Tutankhamun's death, she tried unsuccessfully to marry a Hittite prince rather than accept Ay.
The entire storyline of the battle, the capture and all other military goings-on are fictional and are not supported by any evidence of any kind. The struggle for power between the general, the vizier, and the high priest are real but the nature of any military engagements are entirely fictional.