Corrin

The Avatar (マイユニット, Mai yunitto, My Unit in the Japanese version), default name Kamui (カムイ) in the Japanese version, is a playable character in Fire Emblem if. Unlike the Avatar of Fire Emblem: Awakening, who served as a secondary protagonist, the Avatar of if is the main protagonist of the game. Like in Fire Emblem: Shin Monshō no Nazo ~Hikari to Kage no Eiyū~ and Fire Emblem: Awakening, the Avatar's identity is customizable by the player. The male Avatar is voiced by Nobunaga Shimazaki while the female Avatar is voiced by Satomi Sato.

Profile
The Avatar was born to the Hoshido royal family as the third eldest child of five. They were kidnapped as an infant and raised by the royal family of the neighboring kingdom of Nohr. Mysteriously, they have the miraculous ability to shift into a Dragon. As a member of royalty, the Avatar wields the power of Dragon's Vein, allowing them to alter the terrain of a map.

A great war looms over Hoshido and Nohr and soon the two kingdoms meet on the battlefield. The Avatar must choose to side with a kingdom and help with their respective causes.

Hoshido
If the Avatar sides with Hoshido, they will be defending it from the invading Nohr kingdom.

Nohr
If the Avatar sides with Nohr, they must revolutionize the Nohr kingdom from the inside.

Third route
There is a third route, available as DLC, where the character aligns with neither Hoshido or Nohr, but details on this route are currently unknown.

Etymology
In Hinduism, an Avatar is a terrestrial manifestation of a deity. The term is commonly used to refer to an entity that represents the player in a video game.

Kamui is the word for a divine being in Ainu mythology, although it is almost never written with kanji in modern times. In a more general Japanese context, Kamui refers to the might and majesty of the gods, particularly the Shintō Kami. This is more to tie the Avatar's roots to the Hoshido kingdom which is based on feudal Japan.

Trivia

 * Both Avatar's official artwork depicts them wielding Yatogami (夜刀神).
 * The Yatogami's hilt is modeled after a vajra, (meaning both thunderbolt and diamond) a ritual implement in Buddhist and Hindu beliefs meant to symbolize firmness of spirit and spiritual power.
 * The Male Avatar in if is the second playable male unit to wield Dragonstones after Bantu.
 * Both genders of the Avatar are the only Lords that can use Dragonstones.
 * The Avatar's default name in the Japanese version is shared with Kamui from Fire Emblem Gaiden.
 * Interestingly, the class Dark Prince was Julius’s class in Genealogy of the Holy War; while it could be a coincidence, Julius was the imperial prince of Grannvale and vessel of an evil Earth Dragon.
 * The official artwork of the female Avatar shows her having two left feet. This is most likely an overlooked error.
 * The artwork was later modified to show the correct feet.