Medunamun (c. 103 BCE – 48 BCE), also known as The Ibis, was a member of the Order of the Ancients appointed by Pharaoh Ptolemy XIII to serve as the Oracle of Amun in Siwa, Egypt in 49 BCE. Since the true purpose of his tenure was for Ptolemy to consolidate his hold over the remote, dissident town, Medunamun was derided as a false oracle by his enemies such as the Medjay, Bayek.
Under his rule, the villagers of Siwa were subjected to extortion, arbitrary detention, and rampant atrocities. Protests were met by violent reprisals often against an entire family, with whole neighborhoods being razed to the ground. For his part, Medunamun was loyal not to his pharaoh but to his Order, which furiously sought to unlock the Isu vault that lay underneath the Temple of Amun. The Ibis thus played a key role in the death of Bayek's son Khemu in 49 BCE during a botched interrogation of the Medjay. For his complicity in Khemu's demise and his abuses of power in Siwa, Medunamun was assassinated by Bayek in 48 BCE.
Capturing the Medjay
In order to track down the Medjay, the Order had their soldiers catch the boy Chenzira, a friend of Bayek's son, Khemu. Convincing Chenzira and his mother Rebecca that they merely wished to speak with Bayek, the soldiers were led by Chenzira to Halma Point where they overwhelmed the Medjay and captured him. That night, they brought Bayek before an impatient Medunamun at the Temple of Amun. Medunamun in turn led the bound Bayek down to the Siwa Vault where the Order had Khemu hostage and Medunamun himself showed him the Apple, but the Medjay truly did not know the means by which the vault could be opened. In the midst of their interrogation, the group were alerted to the impending arrival of the Pharaoh, Ptolemy XIII.
Medunamun and two others left to delay the Pharaoh, and when they returned, Bayek and Khemu still had not opened the vault. When Bayek broke free of his bindings and flew into a desperate rage at his captors, Flavius redirected Bayek's knife into Khemu's heart, killing him before knocking the anguished Medjay unconscious.
After the incident, Medunamun and his allies presumed that Bayek was dead; in truth, the vengeful Medjay had left Siwa on a quest to hunt down every last one of them. In the meantime, through their influence over Ptolemy XIII, the Order was able to have Medunamun appointed as the new Oracle of Amun in Siwa. This played to both the interests of the Pharaoh and Medunamun: the former wanted to subjugate the deviant village while the latter, with the Temple of Amun as his new base, found himself in the best position to continue studying the vault and how it may be accessed. He forbid his priests from stepping on the oasis with their own feet and even enter the temple, calling it an offense for any but the gods to enter. 
As Oracle of Amun, Medunamun was brutal in his exploitation of the villagers. Increased taxes, as mandated by Ptolemy, were a heavy burden on the poor farmers who, under the leadership of Teremun, rose in protest. Villagers were routinely interrogated and subjected to arbitrary arrests, torture, and abuse. As a consequence for dissent, whole neighborhoods were burned down, and in the words of the town's healer, Rabiah, scarcely a single local had not been beaten by soldiers at one point or another. Moreover, efforts were made to obstruct Rabiah's administration of healthcare including a blockade of the town to prevent the arrival of medical supplies.
Personality and characteristics His iron fist rule over Siwa was draconian yet chaotic at the same time; terror was meted out liberally against its populace while the soldiers felt free to pillage and raze as they pleased.
In spite of his aptitude for horror, Medunamun professed that his underlying motives were righteous. An archetypal Templar in mindset, his goal was to usher in a world under the dominion of the Order of the Ancients, the only individuals he believed could be trusted to be "strong and virtuous". Innocent casualties such as Khemu — in his eyes, merely one boy — were meager sacrifices for the world he dreamed of.
In his strict adherence to rituals, he exhibited a religious zealotry so excessive that his devoutness could scarcely be doubted, yet far from being a fanatic, his faith was insincere. His piety was a mask for not only his sadism — a rather poor one given his public reputation — but his deep-seated insecurities. Though intelligent, Medunamun was wracked by his failure to comprehend the essence of the world around him or the true nature of the gods, especially in light of his role as a priest. His misgivings eventually gave way to a vile bitterness that translated into his quest to shape the world in the vision of the Order of the Ancients.
- Medunamun's name contains the name Amun, the god he supposedly served. Amun, whose name means "hidden one", personified the imperceptible elements of the universe; he later became the national god of Egypt, merging with Ra, under the New Kingdom.