The Avatar is Chrom's right-hand man/woman and the secondary protagonist of Fire Emblem: Awakening. A fully-customizable character, the Avatar becomes the tactician of the Shepherds. His/Her past is a mystery and plays a central role in the game's overarching narrative.
The Avatar (or "My Unit" as it is called in the Japanese version), functions like the similarly player-created character of the Japan-only Fire Emblem: Shin Monshou no Nazo - Hikari to Kage no Eiyuu. The Avatar's default name for both genders is Robin (Rufure in the Japanese version).
In initial character creation, the player can choose the Avatar's gender, build, face, hairstyle, hair color, and voice. The Japanese version of the game includes a special silent protagonist option, where the Avatar communicates with other characters in very vague ways (ellipses, question marks, and exclamation marks).
On the second page of character creation, the player can enter the Avatar's name, birthday (month and day), "asset" (strongest stat), and "flaw" (weakest stat).
Note: For simplicity, the following History section of this article will refer to the Avatar as a male character, as that gender is the default in the character creation process.
At the beginning of the game, the Avatar has a dream in which he and Chrom work together and defeat the evil Validar, but their victory is short-lived when a desperate attack by Validar causes the Avatar to lose control of himself and kill Chrom.
When he awakens, the Avatar is found in an open field by Chrom, Lissa, and Frederick. Having lost his memory, he can remember nothing save his own name, as well as Chrom's. Though this arouses Frederick's suspicion, the Avatar travels with the group, and during a battle with bandits, realizes that he actually has a great deal of tactical knowledge. After being introduced to Chrom and Lissa's sister Emmeryn, the Exalt of Ylisse, he joins the Ylissian militia known as the Shepherds as their tactician.
Over the course of the game, the Avatar and Chrom come to trust each other implicitly, though both are aware that something isn't right as the Avatar suffers from occasional strange headaches, as well as hearing an odd voice in his head. Two years after the game's start, he and Chrom visit a rebuilding Plegia and discover to their surprise that Validar, whom they had previously killed when he attempted to assassinate Emmeryn, has become king. Adding to their surprise, in Validar's company is a figure that looks exactly like the Avatar.
It is ultimately revealed that the Avatar was born with the intent of his becoming the vessel required for the revival of the fell dragon, Grima. However, as a baby, he had been spirited away by his mother, who took pity on him. When Lucina and the other children traveled back in time in order to prevent the oncoming destruction, the Avatar's future self did so as well. The future Avatar had intended to merge with his counterpart in the past, ensuring that Grima's revival would come to pass, but the past Avatar was too weak, and as a result the merging failed and the Avatar lost his memory. But even as Chrom and the Avatar worked to change their future, the future Avatar manages to revive Grima on his own.
After Chrom performs the Awakening ritual with Naga to unlock the full power of the Exalted Falchion, Naga informs the Shepherds that there are two possible ways to stop the fell dragon. If Chrom slays Grima with the Falchion, Grima will be put back to sleep, but will inevitably reawaken one day to threaten the world again. On the other hand, if Grima were to be slayed by his own blood (that is, the Avatar), he would actually be killed and never threaten the world again. However, in doing so, the Avatar would also perish, and would only have the slightest chance of surviving if he shared strong enough bonds with others to keep him from departing the world.
To end the game, the player must slay Grima with either Chrom wielding the Exalted Falchion, or with the Avatar wielding any weapon. If the Avatar finishes the fight and kills Grima, he will vanish, but everyone remains hopeful that he's still out there somewhere. After the credits roll, a short epilogue plays that mirror's the game's opening, with Chrom and Lissa once again finding him asleep in a field. Chrom helps him to his feet and welcomes him back.
Class Abilities and Promotions
Although the Avatar is not a member of the Lord class, the Avatar functions similarly to a Lord character; if he/she dies, it is an automatic Game Over.
The Avatar's starting class is Tactician, which grants the ability to wield both tomes and swords with equal capability. Through the use of a Master Seal, he/she can promote to Grand Master. The Avatar is the only character in the game that can change to any other class (barring gender-specific classes) through the use of a Second Seal.
The Avatar is the only character who can romance every other opposite gender character, including second-generation characters and post-story unlockable characters. Regardless of who the Avatar marries, the marriage will result in the birth of Morgan, a son or daughter whose gender is the opposite of the Avatar's. Depending on who the Avatar marries, Morgan can have a sibling or be an only child.
Super Smash Bros.
The Avatar, using the default name Robin, is playable in Super Smash Bros. for Wii U and Nintendo 3DS. Robin is playable in both male and female form and uses the default Awakening designs for both. He/She fights using magic tomes and a Levin Sword. However, like in Fire Emblem, both tomes and the Levin Sword are of limited use. When the Levin Sword breaks, Robin fights using a Bronze Sword until the Levin Sword regenerates.