Dramatis personae
A quick note: This article assumes basic knowledge of the overall plot to the Metal Gear Solid franchise. I try to summarize where I can, but if you're completely new or want a refresher, be sure to check out this handy, series-encompassing plot synopsis.
Big Boss/Punished "Venom" Snake
Big Boss began his role in the Metal Gear series as its greatest villain, but thanks to decades of sequels, prequels, and retroactive continuity, his role in the timeline has become far more complex. Metal Gear Solid 3 introduces a Big Boss before he received his intimidating title, back when he was known by the callsign Naked Snake. Snake receives the title of Big Boss after saving the day by killing his closest friend and mentor, but then leaves the military and wanders from skirmish to skirmish, eventually forming a secret organization called The Patriots with Major Zero and Revolver Ocelot. Things seem hunky-dory until Zero decides to clone Big Boss without his consent, which doesn't really sit well with him. Big Boss leaves the Patriots, and eventually meets Kazuhira Miller, forming the Militaires Sans Frontieres (MSF), a private military company built for a new age of war.
Which leads us to Ground Zeroes, a brief mission that shows us the destruction of MSF by unknown forces and a helicopter crash that seems to place Big Boss in a nine-year-long coma. Up to this point, Big Boss hasn't exactly gone full-on evil yet. Morally gray and willing to build a massive organization of mercenaries, sure, but he's not finding war orphans, raising them as soldiers, and using them to create more war orphans, perpetuating the cycle of violence ad infinitum like he was in Metal Gear 2: Solid Snake. So how does Big Boss get to that point? The Phantom Pain should shed some light on exactly how Big Boss will avenge his fallen comrades - and considering his new callsign is Punished/Venom Snake, it's probably not going to be pretty.
Ishmael
First revealed in a trailer shown at GDC 2013, Ishmael is probably The Phantom Pain's most enigmatic character - and that's saying something when you compare him to the mysterious rogue's gallery already revealed.
Ishmael is a fellow hospital mate of Big Boss who claimed to be watching over him while he was in a coma for nine years. His face is completely bandaged, and he sounds like he's voiced by Kiefer Sutherland - which, coincidentally, is the same actor who voices Big Boss. Who is Ishmael? Is he another person, or merely a figment of our imagination? Whoever he is, he seems like he holds the key to The Phantom Pain's biggest secrets.
Quiet
The first thing you'll probably notice about Quiet is her clothing - or, more accurately, her lack of clothing. The reason behind her manner of dress is apparently under as much lock and key as the reason why she's unwilling - or unable - to talk, but based on the "Quiet But Not Silent" trailer, it would appear that your crew isn't exactly thrilled to bring her aboard.
What we do know about Quiet is that, at some point in the story, she meets up with Big Boss and joins forces, offering up her crack-shot sniping skills in the field. She'll post up on a cliff face or some form of high elevation, keeping watch for you through her sniper scope, marking enemies, and sending a bullet through their unfortunate faces at your command.
Skull Face
Skull Face doesn't seem like a very nice guy, if the cassette tapes found in Ground Zeroes are any indication. He holed up at Camp Omega for a while, taking time to torture both Chico and Paz, as well as a variety of other POWs and political prisoners. At the beginning of Ground Zeroes, he's seen taking off in a helicopter moments before Big Boss shows up, his face scarred beyond recognition.
Like many of the newly-revealed characters, not much is known of Skull Face, though the E3 2015 trailer does shed some light on his origin. At a young age, Skull Face lost his nation, as well as the language of his native tongue, to foreign soldiers. Because of this, Skull Face wants to rid the world of language, uniting the world under "the chain of retaliation". The events of Ground Zeroes make it seem like he was the one who ordered the bomb to be placed inside Paz, causing the explosion that sent Big Boss into a coma, but then he's seen palling around with Big Boss at the end of that E3 trailer so what the hell is going on?
Benedict "Kazuhira" Miller
This guy seems to get a new name with every single game he's in. Referred to as Master McDonnell Miller in Metal Gear Solid, then Kazuhira Miller in Peace Walker, now he's Benedict Miller. He was second-in-command of MSF during Peace Walker, and after its annihilation at the end of Ground Zeroes, he rejoins Big Boss to pick up the pieces, forming a new private military corporation called Diamond Dogs nine years later. Obsessed with revenge, Miller and Big Boss aim to take down Cipher once and for all in The Phantom Pain.
But here's the thing - eventually, Miller and Big Boss go their separate ways, as Master Miller ends up training soldiers for FOXHOUND, including one Solid Snake, while Big Boss secretly heads up Outer Heaven. Miller even serves as one of Solid Snake's contacts during Metal Gear 2: Solid Snake, going so far as to call Big Boss a "monster" in the final encounter. Miller dies shortly before the events of Metal Gear Solid, as his body is found murdered in his Alaskan home during the Shadow Moses Incident. What caused the schism between the two comrades-in-arms? Or will this bit of information be retconned out of the series' timeline? Hopefully The Phantom Pain will provide some answers.
Revolver "Shalashaska" Ocelot
Introduced in Metal Gear Solid as a bitter rival to Solid Snake, future games in the series would paint him in a far more sympathetic light. He first met Big Boss during Operation Snake Eater, where Ocelot worked as a Russian GRU operative and secret Philosopher spy. After the events of Snake Eater, Ocelot and Big Boss would go on to form the Patriots, along with Major Zero. When Big Boss left, Ocelot remained with the Patriots, though he despised their policies. In the 1980s, he left the Patriots and rejoined Big Boss to help build the Diamond Dogs.
Despite playing villain to Solid Snake throughout his adventures, MGS4 informed us that Ocelot's loyalty always remained with Big Boss. Everything that happened in MGS 1, 2, and 4 - from siding with Liquid and Solidus Snake, to grafting his hand with Liquid's arm and allowing it to take control of his body - was all done to help Big Boss combat the Patriots. He dies at the end of MGS4, thanks to the FOXDIE virus inside Solid Snake's body.
Huey Emmerich
The Emmerich family has a long history with building machines of war. Huey's father was one of the scientists that worked on the Manhattan Project, designing the atomic bombs that would decimate Hiroshima and Nagasaki. Huey would go on to work as a mechanical engineer, perfecting research discovered in Operation Snake Eater that would give way to the bipedal technology found on Metal Gear. He also designed Peace Walker in 1974, believing that it would provide the ultimate form of nuclear deterrence. His son, Hal (or Otacon, as he's also known), would go on to develop Metal Gear REX in Metal Gear Solid - but let's back up a bit.
Big Boss rescues Huey Emmerich during the events of Peace Walker and brings him into MSF to design Metal Gear ZEKE, a nuclear-equipped walking battlemech. Before the events of Ground Zeroes, government organizations are catching wind of MSF and rumors that they may be hiding nukes. Big Boss and Kazuhira Miller dismiss these allegations and deny their requests for an inspection, but Huey sends another message allowing them to go ahead with the investigation, with the team wrapping up as Big Boss returns from his rescue mission at Camp Omega. The investigation was likely a ruse, however, as Big Boss returned to find MSF under attack from an unknown force. Was Huey the reason MSF was invaded, or is he merely a patsy to a larger double-cross?
Eli
Eli's only been shown in a few trailers, and only in a brief handful of scenes, but he is most likely one of the clones created during the Les Enfants Terribles project. More specifically, he's probably Liquid Snake, the villain of Metal Gear Solid. First off, Eli is the right age to be Liquid, considering The Phantom Pain takes place in 1984, and the Les Enfants Terribles project began in the early 1970's. He's blond, he does the same fist-pump-then-hop-into-Metal-Gear bit that Liquid does in MGS, and the back of his jacket has a series of Japanese characters that loosely translate to "liquid man". Oh, and at the end of the E3 2015 trailer, the camera hovers over him and another kid who looks exactly like him, while Big Boss says, "'Les Enfants Terribles', Zero called it." Yeah, the kid has to be Liquid Snake.
Anyway, according to Metal Gear Solid, Liquid Snake and his father Big Boss don't exactly have the best relationship. Liquid feels slighted because he ended up with all of the recessive genes while Solid ended up with the dominant genes, even though Liquid doesn't know that the reverse is actually true. His ultimate wish is to surpass his father and his genetic destiny, and his attempt to do this comes during the Shadow Moses Incident. He ultimately fails, falling victim to the FOXDIE virus harbored inside Solid Snake's body.
Code Talker
Not much is known about Code Talker, but the E3 2013 trailer describes him as a "Wise Man denied his Homeland." He appears to be of Native American descent, and a GDC 2013 presentation suggests that he may be over 100 years old, if the character model they're showing is in fact the same one used for Code Talker. His speech in the E3 2015 trailer mentions that language is the one thing that can bring multiple cultures and nationalities together.
Those who 'Don't Exist'
This is where The Phantom Pain gets a little weird. We've seen video footage from the hospital sequence back at GDC 2013 that shows a young child wearing a gas mask while floating in the air, along with the appearance of a menacing man engulfed in flames (possibly Colonel Volgin, the villain from Metal Gear Solid 3). Is the child Psycho Mantis, the master psychic introduced in Metal Gear Solid? Does that make the man on fire a psychokinetic apparition, or his he real, too? Or is something else going on here?
Paz Andrade
Paz originally called upon Big Boss at the beginning of Peace Walker to help rid her country of a mysterious invading force, but was, in actuality, a double-agent working for Cipher. Her job was to keep tabs on Big Boss, MSF, and the development of Metal Gear ZEKE. When her cover was blown, she tried to make off with ZEKE, attempting to kill Big Boss in the process. Big Boss foiled her plans, and Paz is flung into the ocean in an explosion.
Big Boss learns that Paz survived the blast and is being held prisoner at Camp Omega, a US black site on Cuban soil. Because she knows of MSF's and, subsequently, Metal Gear ZEKE's existence, Big Boss infiltrates the camp to rescue her. After exfiltrating Paz via helicopter, he discovers a bomb planted inside her abdomen, but misses a second bomb - the one that supposedly destroys the helicopter and places Big Boss into a nine-year-long coma. Paz should surely be dead, right? Well, footage from the E3 2015 trailer shows a Paz who looks very much alive, and who hasn't aged a day since the incident in 1975.
Chico
Big Boss meets Chico during the Peace Walker Incident during a rescue mission. Chico's older sister, Amanda, was a comandante for the Sandinista National Liberation Front, and urges Big Boss to rescue her brother from the enemy's clutches. Big Boss finds the young boy weeping, having sold out the location of his comrades. Big Boss takes pity on him, recruiting him to fight alongside him with the rest of MSF. It's there that Chico befriends and develops a crush on Paz.
Fast forward to Ground Zeroes. Chico learns that Paz is being held at Camp Omega, and so he leaves on his own to find and rescue her, inevitably getting captured as a result. Big Boss rescues Chico along with Paz, and exfiltrates via chopper. He witnesses the destruction of MSF along with Big Boss, Paz, and Kazuhira Miller, and is inside the helicopter when the bomb hidden inside Paz goes off. Chico's fate is currently unknown.
Major Zero
Major Zero was a British SAS officer and MI6 operative before joining the CIA and heading up the FOX Unit, a black ops squad specializing in infiltration, along with The Boss. He was Naked Snake's commanding officer during the events of Metal Gear Solid 3, and would go on to form The Patriots after Revolver Ocelot recovered the Philosophers' Legacy.
While Major Zero and Big Boss were allies for a time, Zero's Les Enfants Terribles cloning project created a schism between the two, causing them to become bitter rivals. Zero renamed The Patriots to Cipher and went into hiding, using proxies to relay orders to his operatives. Cipher and Big Boss would spend the next several decades fighting with one another, beginning with the Peace Walker Incident in 1974. Their conflict would eventually come to a head in 2014, as Big Boss finally ends Major Zero's life, putting a stop to The Patriots and Cipher once and for all.
While there's no word on whether Major Zero will actually make an appearance in The Phantom Pain, Skull Face and Paz make several references to Cipher throughout various cassette tapes in Ground Zeroes. Major Zero may never show his face, but it's likely that Cipher's shadow will hang over the proceedings like a storm cloud, and it's there's a good chance that this is his voice in the E3 2015 trailer, describing how he's found a way to make "the Boss' vision a reality".
