Proto-Keymind (Earth-5875)

"What's that... thing? Brett..."

- - Ellen Ripley and a dying Arthur Dallas

The Proto-Keyminds, also known as the Brain form or the Compound intelligence, is an advanced xenomorph variant generated after the biomass of the most intelligent is made available, with the intent of evolving into a functional Keymind.

Overview
Proto-Keyminds are formed when the xenomorph acquired enough biomass and minds to be fully sapient. To create this viable mind, lesser xenomorph variants merge together with their late hosts in a hive, using the combined knowledge of all impregnated hosts. They are formed to operate under difficult circumstances and to perform advanced tasks, such as picking and using enemy weapons, piloting starships, where the xenomorphs searches to impregnate hosts with this knowledge, such as soldiers and pilots. They do not completely destroy the consciousness of their victim, but rather slowly interrogates them, allowing the nervous system to feed information, releasing a loud buzzing sound used to torture the victim and erasing all of their memories. Once the victim is stripped from the essence of their own character, the Proto-Keymind kills them.

While normal xenomorph forms are able to clumsily pilot enemy vehicles, Proto-Keyminds are able to man complex vehicles which require trained pilots, such as starships. However, because they are stationary, they use the nearest combat variants to pilot them, as well as planning battle strategies. Unlike all other known xenomorph variants, Proto-Graveminds are passive and immobile, never attempting to directly defend themselves; it is believed that until its transformation to a full Keymind, Proto-Keyminds are merely a mixture of harvested bodies. They are also able of jamming communications and distorting radio signals. Despite the they do so remain unknown, it is believed it has something to do with the inexplicable telepathy the flood use to communicate with each other.

History
Proto-Graveminds have been encountered in a number of times through galactic history.

Massacre on the Nostromo
"I'll get you out of here! Kill me... please... I don't... I can't take it anymore."

- - Ellen Ripley and Arthur Dallas The first recorded encounter with a Proto-Keymind occurred on June 16th, 2528, at the massacre on the Nostromo: the Alien, born from Thomas Kane, captured both Samuel Brett and Arthur Dallas, taking the two to the depths of the Nostromo, where it created a hive to place them. When Ellen Ripley activated the ship's self-destruct system and rushed to the shuttle Narcissus, she stumbled upon the hive, finding Brett, fully converted into xenomorph biomass, and Dallas, still resisting the Proto-Keymind's powerful mental torture, which wanted information of worlds to spread its infection. There, Dallas informed Ripley that he could not resist for much longer, and begged her to kill them both. Crying and reluctant, she eventually burned them to death with a M7057 flamethrower, killing the two and the Proto-Keymind in the process.

Battle of Etran Harborage
During the massive Battle of Etran Harborage on February 23rd, 2531, the Covenant and the crew of the UNSC Spirit of Fire stumbled upon a massive xenomorph outbreak on the shield world Etran Harborage, where they discovered a massive Proto-Keymind had been forming with hundreds of human civilian and military, as well as Covenant hosts. The Proto-Keymind was incredibly smart, and was on the verge of becoming a Keymind. The creature was eventually destroyed by the UNSC thanks to the Sergeant John Forge and alongside SPARTAN-II Red Team. It was able to duplicate the transponder signal sent by Professor Ellen Anders to lure the human forces and impregnate them. Its remains were pulverized when Sergeant Forge destroyed the Spirit of Fire's makeshift Shaw-Fujikawa Translight Engine bomb, destroying the entirety of Etran Harborage and taking all Covenant and xenomorph forces with him.

Battle of Installation 04
"Jacob... Captain service number 01928-19912-JK... You will NOT have me... «We already do.»"

- - Captain Jacob Keyes and the Proto-Keymind During the Battle of Installation 04, the xenomorphs that escaped the ring's containment facilities were able to capture numerous human and Covenant forces, eventually forming a Proto-Keymind aboard the Covenant CCS-class battlecruiser Truth and Reconciliation, with the intent of allowing them to pilot the ship and spread beyond the ring. The Proto-Keymind assimilated Captain Jacob Keyes and tortured him in an attempt to learn the coordinates to populated planets, including Earth. Despite fighting with all of his remaining will to prevent the xenomorphs from gaining the information, he eventually perished to the parasite as the Proto-Keymind eventually discarded and erased all the memories of his life, such as his childhood, his romance with Catherine Halsey and the existence of his daughter, Miranda. John-117 and Cortana just in time as the Proto-Gravemind was extracting the memory it wanted from Keyes, punching through the Captain's skull to take his neural interface. Moments later, the Proto-Keymind was destroyed by Silent Shadow forces led by Zuka 'Zamamee.

Raid on the Infinite Succor
At the same time, another Proto-Gravemind started being formed at the Covenant DSC-class support ship Infinite Succor, composed of remnants of unggoy, sangheili and human hosts, as well as animals that would serve as food for the vessel's crew. The Proto-Gravemind was constructed at the Succor's engine room, as the command center was incassible to the xenomorphs. As soon as it formed, it created more xenomorphs, that, in the Coordinated Stage, killed the un-impregnated ship members, including dozens of huragok, and later captured the san'shyuum leader, the Minister of Etiology, to extract the location and coordinates to Covenant worlds. Before it could do so, the Proto-Gravemind was destroyed by Special Operations Commander Rtas 'Vadumee, at the cost of his left jaws, his whole squad, and his best friend, Bero 'Kusovai.

Raid on the Mona Lisa
Another Proto-Keymind was created on the penal ship Mona Lisa days following the destruction of Installation 04. The xenomorphs that roamed the ship impregnated most of the crew's staff, scientists and prisoners, in an attempt to access the slipspace drive of the ship by kidnap UNSC pilots and letting the Gravemind assimilate their memories, but they were stopped and destroyed by Ncog Benti with fragmentation grenades.