I’m here to talk about the Prisoner of Charum Hakkor and the connection he shares with the Gravemind, perhaps leading them to be one and the same. Prepare yourselves for a rather lengthy post:
The Terminals state that Mendicant Bias conversed with the Gravemind for 43 years before forcing itself into Rampancy, defecting to the Flood and betraying the Forerunners. I find it to be far beyond coincidence that the test-firing of Installation 05 at Charum Hakkor - and thus the release of the Prisoner - occurred at the same time and they conversed also for 43 years.
Gravemind states in Human Weakeness that he has consumed many AIs but spared one who joined him long ago, obviously referring to Mendicant Bias.
Primordium’s description states that humans call the Prisoner “The Primordial”, this is the same name Major John Smith uses to describe the Flood in The Mona Lisa.
The Prisoner is known as “the Timeless One”, Gravemind describes himself as a “timeless chorus”.
Gravemind states he has “listened - through rock and metal and time”, the Prisoner listened to the humans and San’Shyuum at Charum Hakkor in his prison for a very long time.
The last words of the Gravemind is “resignation is my virtue; like water I ebb, and flow. Defeat is simply the addition of time to a sentence I never deserved… but you imposed.” The latter part is referring to imprisonment, a sentence he never deserved. The PRISONER of Charum Hakkor, locked away for unknown reasons.
Mendicant Bias given charge of Installation 05 (his serial number was 05-032), the Prisoner stowed away on the Installation he stole - the same Halo we discover the Gravemind on 100,000 years later.
“Child of my enemy,” is a reference to Ancient Humanity - the first foe the Flood fought and lost against.
The Gravemind was in containment on Installation 05 and escaped when Penitent Tangent ignored his containment protocols. The Gravemind cannot have been formed after the breakout because there was no sentient life living there.*
In the Bestiarum, they have the Spartans labled as "Unclassified. You can tell they mean Spartans because they list them as “-skiska, u got it good!- sapiens augeous”. You can tell from the “augeous” they mean augmentations. Another curious thing to note is that they label them as Reclaimers. Anyways, even though they’re labeled as a separate people it still says “Ties with group - Human”.
However if you check out the Gravemind which is separate from the Flood like the Spartans, it doesn’t say “Ties with group - Flood”. He remains his own separate species.
In fact, in a physical sense, I don’t think the Prisoner was ever physically present, but rather using the Gravemind as a conduit for his mouth. The giant venus fly trap we see in Halo 2 got completely obliterated twice, once in the Forerunner era and once in the contemporary era, yet the Gravemind still survived. And before you say the GM in Halo 2/3 is not the same as the Forerunner one, it is.
Three things: Firstly, the Proto-Graveminds are a physical entity that requires much more substantial amounts of biomass to be created then what was present at 05. Second, when the Proto-GM dies, everything in the local Flood hive else dies, and it can be killed by conventional means, which the real GM cannot. Third, he speaks as if he’s extremely old and has experienced all things the Flood did 100,000 years ago and even before then.
The venus flytrap is a mouth organ, for him to speak verbally to the Chief and Arbiter. That was “destroyed” in Halo 3 during the High Charity explosion, yet GM survived again and begun rebuilding itself on the Ring. Installation 05, I believe was also glassed to kill off the Flood. He survived that too. And, according to him at the end of Halo 3, he survived the Halo detonation as well.
All of this indicates the Gravemind might not truly have ever been present, and that he was somewhere else, a long way from possibly even the galaxy, projecting his mind into the Flood.
Its this case with the Besterium that originally lead me to believe that the Gravemind was not actually present at Installation 05, High Charity or 04b, but rather the Prisoner was somehow psychically projecting his consciousness, or a part of it as the GM can apparently do so with individual Flood, to converse with Cortana.
TL;DR Gravemind is the Timeless one.
