Please note, the following article contains spoilers for the main story of Warframe, starting at the Second Dream and ending with The Sacrifice
The Man in the Wall is first mentioned by Rell during the Chains of Harrow quest, but the idea of a sinister presence in the Void is not a foreign one to the universe of Warframe. The Orokin created the Sentients so that they could cross the Void without risking the same fate as the population of the Zariman Ten-Zero — the adults driven to madness (or worse) and the children changed by their proximity to the unknown powers of the Void. The Man in the Wall is as enigmatic as its place of origin, and the underpinning malice of its presence looms over the Operators, casting doubt on their perception of reality, hinting at and guiding us toward the coming conflict – reminding the Operators that while they are powerful they are not immune to the effects of their birthplace.
The Man in the Wall only appears in-game as a facsimile of the Operator, albeit with small alterations. Some Operators report that the eyes aren’t quite right, and the entity can be found engaged in activities like hand-stands, or sitting on consoles not intended for sitting.
Though the entity does not appear during the events of the War Within, the Man in the Wall speaks through the Operator as they explore the inner sanctum of their memories, and the reality of what the Star Children were to the Orokin. The entity’s nature is partially revealed when the Operator makes their decision regarding the Kuva flask, as it seems to be heavily in favor of only one option that the Operator can take (here’s a clue, the Man in the Wall prefers the Operators take strength rather than relinquish it).
As previously mentioned, the name ‘Man in the Wall,’ is first heard in-game when spoken by Rell at the end of the Chains of Harrow quest. It is revealed that Rell spent his life (and death) subduing The Man in the Wall; protecting the other Operators from its presence and therefore its influence. After the events of this quest, the Man in the Wall is no longer restrained by Rell and has been free to assert itself on the Operators, interfere with events, and push Operators in whatever direction serves its ambiguous goals best.
After the Sacrifice quest, the Man in the Wall speaks to the Operator and confirms that its intentions are still confusing. The entity verifies the information learned by the Operator, memories that are unsettling and speak to the origins of Warframes and the Operators themselves and proclaims only “Good.” before disappearing.
The most prevalent theory of the Man in the Wall is that it is an embodiment of the Void brought to form by the introduction of the Zariman Ten-Zero and the Operators. The entity is a harbinger of the dangers of the Void whose only goal seems to be destruction and chaos. The entity adapted behaviors of the Operator’s father as a means of ingratiation with the Operator – a way of pushing their buttons and antagonizing them while also adopting a watchful presence.
Theories exist that the Man in the Wall is one of the major villains the Operator faces through the story, manifesting their intentions through the Void. The most prevalent version of this theory is that Ballas is behind the Man in the Wall, guiding the Operators down a path that would allow the Lotus to leave her post and kick off the events of the Sacrifice.
Personally, I believe the first theory is the more likely correct, albeit in a limited capacity. I believe the Man in the Wall as an entity is a psychological manifestation of the Operator’s need for a guide, as well as their buried survival instincts that would have been invaluable on the Zariman Ten-Zero. However, due to the Operator’s proximity to the Void, this manifestation has taken on a life of its own – similar to a thought-form often mistakenly referred to as a Tulpa.
This thought-form manifestation of the Operator’s id would naturally have no motivation except to guide the Operator’s towards more power, greater knowledge, and strength. Rell would have held this manifestation at bay in order to keep not only the Operators safe, but also to maintain the safety of the entire solar system. Unchecked, the Operators could level the entire system, and become a second Orokin Empire to rival the first if they were to be constantly exposed to their own buried desires for power and conquest… their disorganized instincts to survive and become stronger.
I theorize that the Man in the Wall is no more and no less than the result of the Operator’s being trapped in the Void long enough that their powers created a new being in their own image, with all of the characteristics of the Void imbued with the instincts and desires that the Operators try desperately to keep in check, lest they become what they are fighting against. In this way, the Man in the Wall is neither good nor evil, but exists as the antithesis to the control the Operators have gained over the years. The Man in the Wall is the voice in our ear telling us that we need to be stronger, no matter the cost.
The Man in the Wall is a significant figure no matter what it turns out to be in reality. It guides the Operators along their journey after the War Within, and has become more and more prevalent and intrusive as time has gone on. With the destruction of Rell, the Man in the Wall has been left unchecked and challenged only by the Operators that were previously kept from its influence. What this means is that the entity now has a much wider audience to influence, and the likelihood that one of those ears may be bent is much greater than before. The Man in the Wall has no discernable goal, but this may change in time. Perhaps the Operators will have a significant choice in the future regarding the Man in the Wall or perhaps the Man in the Wall will push us along so subtly that there will only ever be one choice that makes sense.