The Raven

The Raven is a fan-made title given to the player character of every Armored Core game.

Overview
Regardless of any circumstances, The Raven is never given a name, age, face or gender (though often implied to be male), nor does he ever speak, and is simply referred to by all other characters as Raven. The only exception is Leos Klein, who is The Raven of Armored Core: Master of Arena. The capability of each Raven depends on the player, though in every AC game the said Raven prevails as the "perfect weapon"; becoming either a "savior" or "destroyer".

Through the course of Armored Core history, each Raven from their respective title ultimately find themselves attaining feats that are supposedly impossible; dethroning the notorious rank 1 AC Nine-ball thus branding them the title "Nine Breaker," saving the world from destruction, opening a path to freedom, and even to things some would consider as trivial, releasing an ally from their suffering and mere survival instinct.

Armored Core
The Raven appears during the Murakumo/Chrome conflict and proceeds to fight for one of the corporations. He eventually is tricked by Boss Savage into taking a mission he was not supposed to complete. Regardless, he destroys 2 Nine-Balls as well as a computer.

Armored Core: Project Phantasma
The Raven accepts a mysterious request from an unknown client, later revealed to be Sumika. He then proceeds to help her crush the Doomsday Organization. He repeatedly fights enemy irregular Stinger multiple times and finally destroys Project Phantasma.

Armored Core: Master Of Arena
Unlike in previous incarnations, The Raven's sole purpose is to kill Nine-Ball as revenge for killing his family. Over the course of the story, he crushes many Ravens, including Nine-Ball and his Seraph version. With the defeat of Nineball, he becomes the first ever "Nine Breaker" in the Arena.

Armored Core 2
The Raven is a mercenary who comes to Mars and is eventually caught up in the Civil Commotion of Mars. He single-handedly crushes the Frighteners and then proceeds to stop Leos Klein's plans as well as defeating him in AC to AC combat twice.

Armored Core 2: Another Age
The Raven works first for the Corporations and then the terrorist group Union. He defeats the Controller Agents and then destroys The Controller itself, allowing humanity to access the surface.

Armored Core 3
The Raven works in cooperation with the Corporations to investigate what lies beyond the Silent Line. He defeats multiple I-C003-INs, enemy Ravens, and finally the IBIS, thus freeing the second Layered.

Armored Core: Silent Line
The Raven takes part in the Mirage/Navis conflict, decimating Crest and Mirage as well as Navis, destroying a Massive MT, crushing the Crest exclusive Ravens, Crest's Regional division, defeats the #1 Arena Raven Genobee, as well as destroy a Prototype Pulverizer. He is also the first to be implied to have been KIA after fighting numerous Unmanned Suicide Weapons.

Armored Core: Nexus
The Raven takes part in the Mirage/Navis conflict, decimating Crest and Mirage as well as Navis, destroying a Massive MT, crushing the Crest exclusive Ravens, Crest's Regional division, defeats the #1 Arena Raven Genobee, as well as destroy a Prototype Pulverizer. He is also the first to be implied to have been KIA after fighting numerous Unmanned Suicide Weapons.

Armored Core: Formula Front
Instead of being a Raven, the protagonist is an architect for a new team. The Architect helps the his team make it to the Regular League and defeats numerous other teams before finally defeating team Arti, thus becoming the #1 team in the Regular League.

Armored Core: Last Raven
The Raven operates during the Alliance/Vertex war and in the course of 24 hours, he kills many Ravens and defeats multiple Pulverizers. He is also responsible for destroying the Internecine and fighting the 2nd Aerial Pulverizer. By the end of the 24 hours, he is the Last Raven in existence.

Armored Core 4
Rescued by Fiona Jarnefeldt, The Raven works as a LYNX for Anatolia, and is hence known as "Anatolia's Mercenary". His actions contribute to the initiation of the Lynx War, in where he defeats many other LYNXs, including Berlioz and his elite squad. In addition to his impressive kill count, he single-handedly destroys Rayleonard and severely cripples BFF. After defending Anatolia from Joshua O'Brien's 00-ARETHA, he leaves Anatolia with Fiona.

Armored Core: For Answer
The protagonist of Armored Core: For Answer was never mentioned to have been a mercenary pilot at the time Normal ACs where at their epitome, and so is not considered a Raven. The default name for their NEXT is "Strayed".

Anatolia's Mercenary returns as a Non-Playable Character, now working for Line Ark and known by his NEXT's name "White Glint". He is defeated by either CUBE or Strayed, although his death isn't confirmed; yet, it's possible that he will return as one of the protagonists or non-playable characters in the following games.

Armored Core V
Although not initially stated to be a Raven (later referred to as the "Dark Raven" in Verdict Day), the protagonist of Armored Core V is an AC pilot that comes from an elite family of Mercenaries. At first he worked for the Corporation for at least one mission, but changed sides to the resistance and worked exclusively for them. While working for the Resistance, Fran and Rosary served as his operators, with Rosary also providing logistical support with her helicopter.

At the beginning of the game, the mercenary seems to have an almost precognitive dream about his final battle with RD.

In Armored Core Verdict Day, the protagonist of Armored Core V is referred to as "The Dark Raven" by Blue Magnolia.

Armored Core Verdict Day
The protagonist of Armored Core Verdict Day is (presumably) also a mercenary, partnered with Fatman and Magnolia Curtis (Stork Pilot and retired mercenary, respectively). He/she goes on multiple, unrelated missions, being secretly eyed at by the Foundation and Reaper Squad. During the course of the story, he/she defeats approximately 40 other Mercenaries. He/she eventually all but eradicates the Reaper Squad single-handedly, and heavily damages the Foundation; unintentionally causing the self-termination of the scientific faction's "spokesman".

It's understood that, once he/she defeated the Leader of the Reaper Squad, the protagonist and Fatman undertook a "personal mission" with the purpose of destroying all the automatic weapons and save mankind from destruction. Whether they succeeded in this mission is unconfirmed at this time.

Trivia

 * The Raven has appeared twice as NPCs: the first is Leos Klein, and the other is Anatolia's Mercenary.